Flow battery with a dynamic fluidic network

ABSTRACT

Provided are flow batteries that include a fluidic train within a dynamic fluidic network system which fluidic train is convertible between a first state and a second state, the first state the first state placing a main electrolyte source and a dynamic fluidic network, outside the fluidic train and an electrode region, into fluid communication with the electrode region and the second state placing the main electrolyte source and the dynamic fluidic network, outside the fluidic train and the electrode region, into fluid isolation from the electrode region and placing the electrode region into fluid communication with a sampling segment. Also provided are methods of operating flow batteries.

TECHNICAL FIELD

This disclosure relates generally to the field of flow-battery energystorage systems.

BACKGROUND

Flow batteries, such as redox flow batteries, are rechargeableelectrochemical energy storage systems that utilize the flow ofelectrolytes in which electrochemical reactants, typically redox activecompounds, are dissolved. These electrolytes are separately contained innegative electrolyte and positive electrolyte streams and are circulatedthrough respective half-cells of an electrochemical cell whereelectrical energy is either converted to or extracted from chemicalpotential energy in the reactants by way of reversible reduction andoxidation reactions in the electrochemical cell at ambient or nearambient temperatures.

The separation of energy and power in a flow battery provides anarchitectural advantage over sealed batteries, affording independentsizing (specification) of power and discharge duration for a given flowbattery and flow battery system. This can in turn improvecost-effectiveness of long-duration projects and applications sincepower equipment is relatively expensive (on a $/kW basis) andelectrolytes with dissolved active compounds are relatively inexpensive.Additionally, flow batteries are not subject to the capacity fadeassociated with structural/morphological changes caused by cyclingsealed batteries.

In flow batteries and flow battery systems (especially larger systems)that may comprise multiple electrochemical cells (or stacks), it isuseful to monitor characteristics of each of the electrolytes. An inlinemeasurement of an electrolyte's characteristics (e.g., SOC, pH,turbidity, etc.) can provide diagnostic insight for a flow battery thatis not available in sealed batteries, as sealed batteries permitobservation of voltage and may not allow for other active diagnostics ofelectrolytes and/or their active materials during use.

For example, it may be desirable to monitor the state-of-charge (SOC) ofeach of the electrolytes, e.g., to know when the flow battery is “full”or “partially charged” or “empty” before actually realizing thesestates. It may also be desirable to monitor an electrolyte's SOC in realtime so as to identify and, when possible, mitigate parasitic losscaused by excess electrolyte flow or other issues within the system.Monitoring the SOC could also be used to create a reference state forbattery health and/or capacity. The SOC of the electrolyte expresses theconcentration ratio of charged active material to charged and dischargedactive material, and is a useful parameter for describing what fractionof a battery's capacity is utilized in storing energy. If all the activematerial is discharged, the electrolyte is said to have a state ofcharge of 0%, and if all the active material is in the charged state,the state of charge is 100%. At an intermediate state-of-charge(0%<SOC<100%) there will be a non-zero concentration of both chargedactive material and discharged active material.

It may also be desirable to hold an arbitrary SOC. For example, it mayalso be desirable to de-energize the stacks during idle periods forsafety and to limit parasitic reactions (e.g., H₂ evolution).Conventional methods include leaving electrolyte in communication withelectrochemical cell(s) and electrically disconnecting (cells return toopen-circuit voltage); however, this method may lead to highself-discharge, voltage remains on stacks, and uncontrolled voltage thatcan lead to degradation or inefficiencies. Draining electrochemicalcell(s) on shut down (e.g., elevate cell(s) and gravity drain toexternal tanks) is another conventional method to control SOC; however,packaging and structural design constraints, and wet/dry cycling ofstacks can lead to degradation and or flammability issues (H₂ from tankheadspace), such that there is a continuing need for improvements overconventional methods.

Further, because flow batteries require flowing electrolyte, instruments(such as inline instruments) can be used as part of a control system tooptimize electrolyte flow rate. This can reduce the pumping losses andimprove round-trip efficiency (energy recovered/energy input).

In existing flow batteries and flow battery systems, however,improvements to system process controls and fine process controls anddiagnostics are still needed. Further, the shutdown and/or maintenanceof existing flow batteries and flow battery systems can require drainingthe electrolyte from the main electrolyte sources (which can berelatively large) and from the electrochemical cell(s) in which theelectrodes, membranes, current collectors, bipolar (and monopolar)plates, and other components reside. Such electrolyte draining can,however, be time-consuming and expensive, and can also require takingall or part of the flow battery or flow battery system off-line duringthe time that the main electrolyte sources and/or electrochemicalcell(s) are being drained, as well as off-line during the time forre-filling with electrolyte and bringing back to operating condition,such as for start-up.

In addition, the need to occasionally drain main electrolyte sourcesand/or electrochemical cell(s) can require that flow batteries and flowbattery systems are constructed such that the main electrolyte sources(such as tanks) and/or electrochemical cell(s) are at a height relativeto the ground so as to facilitate gravity-assisted draining of theelectrolyte. Such constructions can be expensive and cumbersome, and theneed for elevated system architectures can limit the locations forconstruction.

The operating performance of flow batteries and flow battery systems canbe impacted by a number of factors. In many aspects, these factors maynot be independent of one another. To maintain high performance of flowbatteries and flow battery systems, reduce operating and structuralburdens, and maintain safety of operators, a number of diagnostic,treatment, and system controls are desirable in a flow battery or flowbattery system. Illustrative, non-limiting examples of detection,measurement, and control instruments and systems that are compatiblewith flow batteries and flow battery systems include: (i) an electrodein a balancing (or rebalancing) cell, which may be configured togenerate O₂ within a half-cell chamber of the balancing cell; (ii)instruments to determine a ratio of oxidized and reduced forms of aredox couple in an electrolyte; (iii) instruments to measure a rate ofchange in equilibrium reduction potential of a half-cell of anelectrochemical cell as charge is passed into an electrolyte solutionwithin the half-cell and optionally correlating that measured rate ofchange with the SOC of the half-cell; (iv) a balancing cell forgenerating protons and hydroxide ions to correct pH fluctuations broughtabout by parasitic reactions, where pH of two electrolytes may beadjusted in this manner simultaneously and/or sequentially; (v) abalancing cell for adding or removing solvent to or from an electrolytesolution, such as water with respect to an aqueous electrolyte solution;(vi) instruments to determine SOC of an electrolyte solution in ahalf-cell through various methods; and (vii) systems to regulate andoptimize electrolyte solution flow rates throughout a flow batterysystem, such as half-cells, and that are responsive to measured orcalculated values of voltage (V), current (I), flow rate, and power (P)entering and exiting the half-cell. Flow batteries having a dynamicfluidic network system, as disclosed herein, may include, for example,one or more detection, measurement, and control instruments and systemsas may be needed or desired to fit the needs of any flow battery system.

Accordingly, there is a long-felt need in the art for flow batteries andflow battery systems capable of monitoring multiple aspects of flowbattery fluid flow characteristics and performing system diagnostics, aswell as other operating features. There is also a long-felt need in theart for improved methods of monitoring multiple aspects of flow batteryfluid flow characteristics and performing system diagnostics, as well asother operating features.

Aspects of the present disclosure provide flow batteries, flow batterysystems, and methods that allow fluid volume control; managed flowrates; balancing of plant during operation; control of charge ofelectrolyte during start-up, maintenance, and shutdown; control(including mitigation and management) of shunt current; diagnosticchecks of battery and system components; instruments for control systeminputs and measurements; an alternative to shutdown in response to upsetconditions; assessment of battery and system components; and simplifiedflow battery start-up, by inclusion of a dynamic fluidic network asdescribed in detail below.

SUMMARY

The present disclosure provides, inter alia, solutions to existingproblems and needs for improved fluid flow characteristics, shuntcurrent control, performance, enhanced structural features, andeffective diagnostics and treatment within a flow battery or flowbattery system. In providing these solutions, this disclosure presentsdynamic, structural, diagnostics and treatment, system control, andperformance features of flow batteries and flow battery systems assummarized immediately below.

The disclosure presents flow batteries with a dynamic (i.e., modifiable)fluidic network system and associated dynamic fluidic networks forpositive and negative electrolytes. In some aspects, this dynamicfluidic network system may include flow structures, which may in turninclude subflow structures, such as one or more series subflowstructures, parallel subflow structures, shunt current control subflowstructures (such as for shunt current mitigation and/or management),counterflow subflow structures, measurement and diagnostic subflowstructures, treatment (such as electrolyte rebalancing) subflowstructures, source subflow structures, and drain subflow structures. Insome aspects, the dynamic fluidic network system may also comprisereticulated flow and subflow structures configured in parallel and inseries in relation to each other.

A flow battery has an overall dynamic fluidic network system, which, inaspects, may be described as comprising a first dynamic fluidic networkassociated with a first electrolyte and a second dynamic fluidic networkassociated with a second electrolyte.

In some aspects, the dynamic fluidic network system and its componentshave fluid flow characteristics based on size and volume that vary fromthe flow structures through the subflow structures and further varybetween parallel subflow structures and subflow structures that operatein series. To these ends, the system as a whole has “n” flow and subflowstructures having volumes V₁, V₂, V₃, . . . V_(n) and cross-sectionalareas A₁, A₂, A₃, . . . A_(n) that define size and volume capacity.Generally, in regions of each dynamic fluidic network the flow andsubflow structures will vary from relatively large to progressivelysmaller, while in other regions, the progression will be from relativelysmall to progressively larger, and others will maintain similar sizing.The architectures of flow and subflow structures in a dynamic fluidicsystem or network in no way limits source volumes (including tanks, oreven multiple tanks) or the volumes of liquid electrolyte that may bedelivered to and removed from cells or stacks to achieve desired results(and therefore do not limit achieving desired operational metricsincluding electrical power outputs and charge/discharge cycle times).

Subflow structures comprising an instrument (non-limiting examples beingmonitors, sensors, processors, controllers) to measure one or morecharacteristics of an electrolyte are measurement or diagnostic subflowstructures. In some aspects, the subflow structure may be placedrelatively close to and in fluid communication with the electrochemicalcell(s). In certain aspects, this subflow structure has an electrolytevolume that is less than the total volume of the respective dynamicfluidic network. This subflow structure allows the flow battery to makestate of charge swings rapidly without having to charge or discharge themain electrolyte source and/or regions of the dynamic fluidic network.This subflow structure may fluidically communicate with other flow orsubflow structures, or may be placed in fluid isolation from one or moreof them. In other aspects, a measurement or diagnostic subflow structuremay comprise or be associated with multiple instruments to measure thesame or different characteristics of the electrolyte. In certainaspects, exemplary characteristics include pressure, conductivity,color, temperature, turbidity, viscosity, ground-reference potential,density, concentration, water activity, oxidation-reduction potential(ORP), pH, state of charge, and combinations thereof. As described infurther detail below, some or all of the instruments and controls may belocated outside a fluidic train or sampling segment, and thoseinstruments outside may be associated with electrolyte in the fluidictrain or sampling segment. In aspects, a first fluidic train including afirst sampling segment is associated with a single half-cell; inaspects, they may be associated with more than one half-cell. Inaspects, a second fluidic train including a second sampling segment isassociated with a single half-cell; in aspects, they may be associatedwith more than one half-cell. In aspects, all the instruments arelocated outside of a fluidic train.

In further aspects, the disclosed approach allows an operator to performdiagnostics with a diagnostic subflow structure on other regions(sub-units) of the flow battery and its dynamic fluidic network system,and also allows an operator to energize and/or de-energize sub-units ofthe flow battery without significantly affecting the flow battery orflow battery system as a whole.

As explained above, existing methods for achieving the foregoing includefully draining the main electrolyte source and/or the electrochemicalcell(s) (stacks), which in turn requires transferring containers andpumps to return the electrolyte to the flow battery. The disclosedapproach represents a significant improvement over existing approaches,as the disclosed approach allows for finer control over the process withvery little waste of energy and electrolyte to achieve a more precisecontrol. This subflow structure can be installed close to theelectrochemical cell(s) so as to allow for continuous flow within thecells. Such an approach brings the total capacity waste to essentiallyonly the volume of the subflow structure, instead of also including thevolume of the main electrolyte source and the remainder of the dynamicfluidic network. This disclosed subflow structure can also include oneor more control valves, with accompanying control systems to accuratelymaintain capacity.

An example of an anomaly requiring correction (diagnosis and treatment)is charge imbalance. Charge imbalance results from parasitic chemicalreactions or membrane crossover phenomena that disproportionally affectone electrolyte over another. One example of a parasitic reaction thatleads to electrolyte charge imbalance is water splitting, which evolveshydrogen and oxygen. The apparatuses and methods of the instantdisclosure can be used to determine SOC and to remedy any imbalances.This can be accomplished (as described elsewhere herein) withoutnecessarily draining the main electrolyte sources of the flow batterysystem, as those sources (such as tanks) can be placed into fluidisolation from the membrane within which crossover may take place orelectrodes where parasitic reactions may take place so that crossover(if any) and parasitic reactions can be investigated while minimizingthe amount of electrolyte exposed to the membrane or electrode. Chargeimbalances may be corrected by means of a subflow structure comprising arebalancing cell.

Also provided are flow batteries and flow battery systems having dynamicfluidic networks as disclosed above and discussed in more detail below,which comprise one or more of bipolar and monopolar plate assemblies(BPPA and MPPA, respectively). A BPPA has a frame element and an innerplate having two sides, a positive side and a negative side; an MPPA hasa frame element and an inner plate having one side which is eitherpositive or negative. In some aspects, the frame element forms aperimeter around the entirety of the inner plate. The frame element andinner plate are joined together to form a single, unitary, integralstructure, where the two components (frame and inner plate) may besubstantially coplanar. Each side of a BPPA or the active (positive ornegative) side of an MPPA comprise at least six different flowstructures. These flow structures further comprise two subflowstructures wherein the flow structures of each subflow structure arestructurally and fluidically connected in series and form a first andsecond subflow structure on each side of a BPPA or a first and secondsubflow structure on one side of an MPPA. The frame element and theinner plate may be made of different materials, and the inner plate maycomprise one or more electrically conductive materials. In aspects, morespecifically, (a) the bipolar and monopolar plate assemblies havinginlet (source) and outlet (drain) conduits, inlet and outlet manifolds,which may have different flow paths, and inner plate subflow structurescomprising a plurality of “n” inlet and outlet structures with the sameor different volumes V_(n), cross-sectional areas A_(n), lengths L_(n),and paths P_(n) in electrode regions of a half-cell, the plate commonlyhaving a non-conductive border region and an active region, commonly aninner plate; (b) conductive end plates in flow battery cells that canelectronically communicate with other cells in a flow battery cell stackor system; (c) positive and negative flow structures that provideelectrolytes to a multiplicity of cells in a stack or system; and (d)other features as described more fully below. The structure of thebipolar and monopolar plate assemblies may control flow dynamics andshunt currents. The inner plate's structure may have a first flowstructure, a second flow structure, a third flow structure, a fourthflow structure, etc. which may or may not be fluidically connected toeach other, aside from their direct connection to the manifolds, and mayvary in relation to others in terms of V, A, L, and P values.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to provide an understanding of aspects of the presentdisclosure, reference is made to the appended drawings, in whichreference numerals refer to components of exemplary aspects of thedisclosure. The appended drawings are illustrative only and do not limitthe scope of the present disclosure or the appended claims. Forsimplicity and clarity of illustration, features illustrated in theappended drawings are not necessarily drawn to scale. Further, whereconsidered appropriate, reference labels have been repeated among thefigures to indicate corresponding or analogous elements.

FIG. 1 depicts a general schematic of a flow battery having an exemplarydynamic fluidic network system according to one aspect of the presentdisclosure;

FIG. 2 depicts a general schematic of a flow battery having an exemplarydynamic fluidic network system according to a second aspect of thepresent disclosure;

FIG. 3 depicts the flow battery of FIG. 2 with a fluidic train in state1;

FIG. 4 depicts the flow battery of FIG. 2 with a fluidic train in state2;

FIG. 5 depicts the flow battery of FIG. 4 , identifying the fluidictrain and electrode region and additional instruments;

FIG. 6 depicts a general schematic of a flow battery having an exemplarydynamic fluidic network system according to a third aspect of thepresent disclosure;

FIG. 7 depicts a general schematic of a flow battery having an exemplarydynamic fluidic network system according to a fourth aspect of thepresent disclosure with a fluidic train in a third state;

FIG. 8 depicts a general schematic of a flow battery having an exemplarydynamic fluidic network system according to a fifth aspect of thepresent disclosure with an exemplary counterflow structure;

FIG. 9 depicts a general schematic of a flow battery having an exemplarydynamic fluidic network system according to a sixth aspect of thepresent disclosure with an exemplary counterflow structure;

FIG. 10 depicts the flow battery of FIG. 5 , defining x, y, and zcoordinates;

FIG. 11 depicts exemplary monopolar and bipolar plate assembliesaccording to the present disclosure;

FIG. 12 depicts exemplary features of the bipolar plate assembly of FIG.11 .

DETAILED DESCRIPTION OF ILLUSTRATIVE ASPECTS

The present disclosure may be understood more readily by reference tothe following detailed description of desired aspects and the examplesincluded therein.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. In case of conflict, the present document, includingdefinitions, will control. Preferred methods and materials are describedbelow, although methods and materials similar or equivalent to thosedescribed herein can be used in practice or testing. All publications,patent applications, patents and other references mentioned herein areincorporated by reference in their entirety. The materials, methods, andexamples disclosed herein are illustrative only and not intended to belimiting.

As used herein, the singular forms “a,” “an,” and “the” include pluralreferents unless the context clearly dictates otherwise. As such, theterms “a” (or “an”), “one or more”, and “at least one” are usedinterchangeably herein.

As used herein, the term “comprising” should be understood as having itsopen-ended meaning of “including.” The terms “comprise(s),”“include(s),” “having,” “has,” “can,” “contain(s),” and variantsthereof, as used herein, are intended to be open-ended transitionalphrases, terms, or words that require the presence of the namedingredients/steps and permit the presence of other ingredients/steps.However, such description should be construed as also describingcompositions or processes as “consisting of” and “consisting essentiallyof” the enumerated ingredients/steps, which allows the presence of onlythe named ingredients/steps, along with any impurities that might resulttherefrom, and excludes other ingredients/steps. For example, acomposition that comprises components A and B may be a composition thatincludes A, B, and other components, but may also be a composition madeof A and B only.

As used herein, the terms “about” and “at or about” refer to smallfluctuations. It is generally understood, as used herein, that it is thenominal value indicated less than or equal to ±10% variation, such asless than or equal to ±2%, less than or equal to ±1%, less than or equalto ±0.5%, less than or equal to ±0.2%, less than or equal to ±0.1%, orless than or equal to +0.05%, unless otherwise indicated or inferred.For example, “about 10%” may indicate a range of 9% to 11%, and “about1” may mean from 0.9-1.1. The term is intended to convey that similarvalues promote equivalent results or effects recited in the claims. Thatis, it is understood that amounts, sizes, formulations, parameters, andother quantities and characteristics are not and need not be exact, butcan be approximate and/or larger or smaller, as desired, reflectingtolerances, conversion factors, rounding off, measurement error and thelike, and other factors known to those of skill in the art. In general,an amount, size, formulation, parameter or other quantity orcharacteristic is “about” or “approximate” whether or not expresslystated to be such. It is understood that where “about” is used before aquantitative value, the parameter also includes the specificquantitative value itself, unless specifically stated otherwise. Forinstance, “about 5.0” includes 5.0. Other meanings of “about” may beapparent from the context, such as rounding off, so, for example “about1” may also mean from 0.5 to 1.4.

As used herein, the term “substantially” refers to a property having astatistical occurrence greater than about 75%.

All ranges disclosed herein are inclusive of the recited endpoint andall the intermediate values, including decimal values. The endpoints ofthe ranges and any values disclosed herein are not limited to theprecise range or value; they are sufficiently imprecise to includevalues approximating these ranges and/or values.

As used herein, the term “flow battery system,” refers to a flow-batteryenergy storage system comprising the flow battery of the presentdisclosure. In certain aspects, the flow battery system comprises one ormore ancillary systems, such as a heat exchanger, a ventilation system,a power conversion system, a power source/load, etc.

As used herein, the term “electrochemical cell” refers to a devicecapable of either generating electrical energy from chemical reactionsor using electrical energy to cause chemical reactions. Anelectrochemical cell comprises two half-cells, which may be separated bya membrane. An electrochemical cell may comprise electrodes (anode andcathode), a membrane, current collectors, and bipolar or monopolar plateassemblies. Electrochemical cells may be in parallel or in series(commonly called a stack in flow batteries). The term “stacks” refers tomultiple electrochemical cells adjacent to each other, in fluid andelectronic communication.

As used herein, the term “dynamic fluidic network system” refers to anetwork of flow structures and subflow structures through whichelectrolyte may flow to and from the main electrolyte source(s),including within the electrochemical cell.

As used herein, the term “fluidic network” refers to that portion of adynamic fluidic network system associated with a respective half-cell. A“dynamic fluidic network” is a fluidic network with flow paths that maybe modified during operation or as needed. In a stack, a dynamic fluidicnetwork system will have multiple fluidic networks.

As used herein, the term “electrode region” refers to a region of flowand subflow structures disposed within a given half-cell of theelectrochemical cell where ionic current is observed within theelectrolyte (i.e., where the electrolyte is in contact with a regioncomprising a static, non-conductive portion of the assembly, anelectrode, and a separator).

As used herein, the term “fluidic train” refers to a subflow structureof a dynamic fluidic network that may be used to isolate or connectportions of the flow battery. For example, a fluidic train and itsassociated electrode region may be used in connection with the term“diagnostic subflow structure,” especially in relation to FIGS. 2-7 andin detailed descriptions of the content of those figures.

As used herein, the term “sampling segment” refers to a location withina fluidic train where electrolyte at that location may be tested(whether in a discrete manner or in an ongoing or continuous manner) forone or more characteristics of the electrolyte.

As described more fully below, the following structures and otherfeatures are provided herein. The disclosed technology provides a numberof advantages over existing approaches.

Some such advantages are provided immediately below.

1—Dynamic Fluidic Network Systems and Fluidic Networks

This disclosure provides a dynamic (i.e., modifiable) fluidic networksystem comprising fluidic networks with flow structures and subflowstructures with at least one fluidic network configured to be modifiedbetween two or more states with varying flow paths for electrolyte. Someflow and subflow structures may be placed in fluid isolation from otherflow and subflow structures and electrolyte sources as may be requiredby diagnostic instrument feedback or discovered anomalies within orwithout the flow battery or flow battery system that can adverselyaffect the battery or system or any portion thereof. Some flow andsubflow structures may be placed in fluid communication with other flowand subflow structures and electrolyte sources as may be required, forexample, by for ionic communication. The dynamic fluidic network systemmay comprise fluidic networks that are identified as first and second[dynamic] fluid networks, associated respectively, with first and secondelectrolytes.

The dynamic fluidic network system and its associated dynamic fluidicnetwork(s) provide platforms for accomplishing at least one, andpotentially all, of the following, which are intended to be illustrativeof important features of flow batteries and flow battery systems of thepresent disclosure: (i) Fluid volume control; (ii) Manage flow ratesincluding flow rates through half-cells, cells, stacks, includingsmaller structures within cells and half-cells; (iii) balancing ofelectrolyte using a balancing system which may occur while a battery orstack is in operation; (iv) Control charge of each electrolyteseparately or concurrently, such as for shutdown or during maintenance;(v) Shunt current control (including mitigation and management); (vi) Avariety of diagnostic checks of components of the flow battery or flowbattery system; (vii) Instruments including sensors for control systeminputs and measurements, including inline instruments, real-timemonitoring, and instrument calibration, (viii) Provide an alternative toa shutdown in response to upset conditions created by anomalies; (ix)Assessment of fluid battery components; (x) Simplified flow batterystart-up; and (xi) Maintaining different flow patterns in differentparts of the flow battery.

2—Holding Charge while Idle

An example of control charge of each electrolyte is to hold an arbitrarySOC when a flow battery is idle. It may also de-energize theelectrochemical cell(s) during idle periods for safety and to limitparasitic reactions (e.g., H₂ evolution).

One conventional method for doing so is to leave the electrolytes influid communication with the electrochemical cell(s) and thenelectrically disconnect the cell(s), thereby returning the cell(s) toopen-circuit voltage. Some disadvantages of doing so are highself-discharge, having voltage remain on cell(s), and that uncontrolledvoltage can lead to degradation.

Another conventional method for doing so is to drain the electrochemicalcell(s) on shut down (e.g., using gravity to drain the cell(s)). Thereare disadvantages to doing so, e.g., packaging constraints enforced bythe need to arrange the system to allow for gravity draining, the factthat wet/dry cycling of cell(s) can lead to degradation and orflammability issues, such as H₂ present in tank headspace, and the factthat it is generally burdensome to drain cell(s) and re-wet them. Inaddition to raising the tanks for gravity assist, additional pumps,piping, and alternative temporary storage containers may also be needed.

In contrast, the flow battery of the present disclosure may allow forcontrolled shutdown (to an arbitrary SOC) of the small volume ofelectrolyte in communication with electrochemical cell(s), such as in astack. In this way, the cell(s) stay flooded (i.e., wetted), and voltagehazards are eliminated.

3—Upset Conditions

Another advantage of the flow battery of the present disclosure maypertain to the response optionality provided during upset conditions.Rather than abruptly removing power when an anomaly is detected andrisking component damage, a controlled stop and start can be executed bytaking advantage of a diagnostic subflow structure (e.g., to protect thelarger main electrolyte sources and flow structures) under conditionswhere immediate hazard removal is not required.

It is undesirable to have a full shutdown due to an anomaly except in anemergency, such as conditions that could lead to injury or be lifethreatening. This feature allows a partial shutdown to figure out whatthe problem is, without risking damage to half-cells, cells, stacks, orelectrolytes. A bad pH reading, for example, is undesirable but is notlife threatening—resolving the anomaly with a “soft stop” would bepreferred to shut down. While most anomalies will be internal to theflow battery, this disclosure does not exclude methods and systems forresolving anomalies that may be seen as external to the flow battery.

4—Electrochemical Cell Health Checks

Electrochemical cells can fail at times, e.g., due to the crossover ofelectrolytes. The flow and subflow structures of the flow battery of thepresent disclosure can include sensors (pH, oxidation-reductionpotential (ORP), pressure, flow rates, and the like) so that diagnosticscan be performed before restoring fluid communication between theelectrochemical cell(s) and the electrolyte source(s) to avoidpotentially contaminating a large volume of electrolyte. This techniquecan also detect component degradation or failure. Electrochemical cellhealth can also be checked during the first time a flow battery is runby using a diagnostic subflow structure as the electrolyte source, inplace of the larger electrolyte sources. This flow battery and relatedtechniques can also detect electrolyte balancing component failures.

5—Instrument Calibration

The flow battery of the present disclosure may permit instrumentcalibration, such as to run through a full charge-discharge SOC swing,e.g., to set the ORP in the system. A diagnostic subflow structure,which is comparatively small in volume in relation to the total volumeof the system, allows this to be done with limited electricityconsumption. One can also circulate only one electrolyte and therebyswing a single electrolyte through a wide SOC range (in the diagnosticsubflow structure) while the other electrolyte stays in a comparativelynarrow SOC band.

6—Simplified Flow Battery Start-Up

During commissioning, flow battery electrolyte must be pre-charged toincrease SOC and thereby cell voltage from ˜0 VDC, but other referencevoltages can be used, to the minimum voltage required to engage theinverter. The flow battery of the present disclosure may allow this tohappen rapidly and with minimal input power, as one can charge therelatively small volume of electrolyte within a diagnostic subflowstructure so as to engage the inverter. Less desirable alternatives tothe disclosed technology include, e.g., (i) loading active material atelevated SOC, which can be hazardous; and (ii) pre-charging the entireelectrolyte source to the minimum SOC.

In one aspect, the present disclosure provides a (redox) flow batterycomprising: a dynamic fluidic network system comprising a first dynamicfluidic network and second fluidic network, which may be dynamic,wherein the flow battery has a first half and a second half. The firsthalf comprises (i) a first main electrolyte source configured to containa first electrolyte, (ii) a first electrode region configured forelectronic communication with the first electrolyte, and (iii) the firstfluidic network that is dynamic and configured for fluid communicationwith the first main electrolyte source and comprising the firstelectrode region, a first fluidic train, and a first counterflowstructure. The first fluidic train comprises a first sampling segment.The first fluidic train is convertible between a first state and asecond state. The first state placing the first main electrolyte sourceand the first dynamic fluidic network, outside the first fluidic trainand first electrode region, into fluid communication with the firstelectrode region. The second state placing the first main electrolytesource and the first dynamic fluidic network, outside the first fluidictrain and first electrode region, into fluid isolation from the firstelectrode region and placing the first electrode region into fluidcommunication with the first sampling segment. The second half comprises(i) a second main electrolyte source configured to contain a secondelectrolyte, (ii), a second electrode region configured for electroniccommunication with the second electrolyte, and (iii) the second fluidicnetwork configured for fluid communication with the second mainelectrolyte source and comprising the second electrode region and asecond fluidic train. The second fluidic train is configured to placethe second main electrolyte source and second fluidic network, outsidethe second fluidic train and second electrode region, into fluidcommunication with the second electrode region. The second fluidicnetwork may be dynamic and further comprise a second counterflowstructure.

In another aspect, the present disclosure provides a method ofconverting a flow battery having a first half and a second half. Thefirst half comprises a first main electrolyte source, a firstelectrolyte, and a first dynamic fluidic network. The first dynamicfluidic network comprises a first counterflow structure, a firstelectrode region and a first fluidic train that is convertible between afirst state and a second state and has a first sampling segment. Themethod converts the first fluidic train from the first state to thesecond state. The first state placing the first main electrolyte sourceand the first dynamic fluidic network, outside the first fluidic trainand first electrode region, in fluid communication with the firstelectrode region. The second state placing the first main electrolytesource and the first dynamic fluidic network, outside the first fluidictrain and first electrode region, in fluid isolation from the firstelectrode region. While the first fluidic train is in the second state,the method further comprises determining a characteristic of firstelectrolyte that is in fluid communication with the first electroderegion. The second half comprises a second main electrolyte source, asecond electrolyte, and a second fluidic network that may be dynamic.The second fluidic network may be dynamic and comprise a secondcounterflow structure, a second electrode region, and a second fluidictrain.

The disclosed technology may allow for fine control over the processwith very little waste of energy. A diagnostic subflow structure can beinstalled comparatively close to the electrochemical cell(s) and allowfor electrolyte to flow only through the diagnostic subflow structure,including the electrode region of the electrochemical cell(s). Thisbrings the total potential capacity waste to just the volume of thesubflow structure, including the electrode region. The subflow structurecan use one or more control valves, with an accompanying control systemto accurately maintain capacity.

An exemplary flow battery of the present disclosure is shown in FIG. 1 .FIG. 1 is representative only, is not necessarily to scale, and does notshow all flow, subflow, or other structures, but rather showsrepresentative structures, which serve to illustrate one potential setupof the battery as a whole. As shown, a flow battery can include adynamic fluidic network system comprising a dynamic fluid network inwhich various “n” flow and subflow structures have volumes (“V_(n)”) andcross-sectional areas (“A_(n)”), which define size and volume capacityof the structures. Each flow and subflow structure may be configured, inrelation to each other, to flow in parallel or series, depending onfunction.

As shown in FIG. 1 , a flow battery can include one or moreelectrochemical cells 131 that features a separator 109 (e.g., amembrane) that separates two electrodes 107 and 117 of theelectrochemical cell 131. Tanks 1 and 21 can contain a first electrolyteand a second electrolyte, respectively. FIG. 1 further shows a mainsource flow structure 2, parallel and series subflow structures (3, 4,5, 6, 7, 8), measurement (or diagnostic) structures (3, 4, 5, 8), anddrain flow structure 9, as well as interrelationships between them. Eachof the flow and subflow structures may be configured with additionalsubflow structures depending upon the desired function of the flow andsubflow structure.

The measurement (or diagnostic) structures, as depicted in FIGS. 1-10 ,do not show either absolute or relative positions of instruments, but isintended to show that a multiplicity of monitoring, measurement, andother inline (or not inline) and system-related instruments or tools maybe placed in various locations within a dynamic fluid network.Similarly, the electrolyte moving devices (such as pumps), as depictedin FIGS. 1-10 , do not show either absolute or relative positions ofthese devices, but is intended to show that a multiplicity of devicesmay be used to create flow and counterflow of electrolyte within thedynamic fluidic network system. The presence of these measurementstructures and electrolyte moving devices in FIGS. 1-10 should not beconstrued as meaning that either a measurement device or an electrolytemoving device is a requirement of the flow batteries disclosed herein.

Parallel subflow structure 3 can be configured, for example, as acounterflow structure, when appropriately located valves are configuredand activated. In practice there may be a multiplicity of thesestructures, which may be clustered together, spaced apart, or both. Theplacements of these structures in FIG. 1 are not intended to show eitherrelative or absolute placement thereof. Similarly, the parallel andseries subflow structure configuration is not intended to demonstratethat this branching structure is required, rather, it is intended toshow conceptually that one or more subflow structures may deliver anelectrolyte to parallel and/or series subflow structures. Further, theparallel and series subflow structures are not intended to be limitingin number. For example, such structures may supply any number ofadjacent cells in a stack with the same electrolyte. The exemplary flowbattery shown in FIG. 1 may incorporate the features shown in the FIGS.2-12 described in detail below.

As shown in FIGS. 2-5 , there is a diagnostic subflow structure for eachof the first and second electrolytes which may be the same or different,and the related subflow structures may be designated as a firstdiagnostic subflow structure (or first fluidic train and first electroderegion) and a second diagnostic subflow structure (or second fluidictrain and second electrode region). When they are different, there willtypically be a positive electrolyte and a negative electrolyte (positivediagnostic subflow structure with a positive fluidic train, and negativediagnostic subflow structure with a negative fluidic train). Unlessstated otherwise, either the first or second electrolyte may be positiveand the other negative where such electrolytes are present. FIGS. 2-5are simplified schematic diagrams that focus on the diagnostic subflowstructures and do not show the relationship between the subflowstructures and the larger dynamic fluid network.

An exemplary flow battery of the present disclosure is shown in FIG. 2 .FIG. 2 is representative only, is not necessarily to scale, and does notshow all flow, subflow, or other structures, but rather showsrepresentative structures, which serve to illustrate one potential setupof the flow battery as a whole. As shown in that figure, a flow batterycan include an electrochemical cell 131 that features a separator 109(e.g., a membrane) that separates two electrodes 107 (which includesflow plate 105, which accommodates an electrolyte from tank 101) and 117(which includes flow plate 115, which accommodates an electrolyte fromtank 121) of the electrochemical cell 131. The flow plates are typicallya BPPA or MPPA. An electrode is suitably a conductive material, such asa metal, carbon, graphite, and the like. Tank 101 can contain a firstelectrolyte (not shown), which comprises a first active material capableof being cycled between an oxidized and reduced state.

A pump 103 can effect transport of the first electrolyte comprising afirst active material from the tank 101 to the electrochemical cell 131.The flow battery can also include a second tank 121, which contains asecond electrolyte comprising a second active material. The secondactive material can be the same as the first active material, thoughthis is not a requirement. A second pump 113 can effect transport of thesecond electrolyte to the electrochemical cell 131. Pumps can also beused to effect transport of the electrolytes from the electrochemicalcell to the tanks of the battery. Other methods of effecting fluidtransport—e.g., siphons, gravity—can be used to transport electrolyteinto and out of the electrochemical cell. Also shown is a power sourceor load 140, which completes the circuit of the electrochemical cell andallows the user to collect or store electricity during operation of thecell. An exemplary power source or load includes non-flow batteries.

Exemplary separators are generally categorized as solid, porous, or acombination thereof. Solid separators in the form of solid membranes maycomprise an ion-exchange membrane, wherein an ionomer facilitates mobileion transport through the body of the polymer. The facility with whichions conduct through the membrane can be characterized by a resistance,typically an area resistance in units of Ωcm². The area resistance is afunction of the membrane's conductivity and the membrane's thickness.Thin membranes are desirable to reduce inefficiencies incurred by ionconduction and therefore can serve to increase voltage efficiency of theenergy storage device. Active material crossover rates are also afunction of membrane thickness, and typically decrease with increasingmembrane thickness. Crossover represents a current efficiency loss thatmust be balanced with the voltage efficiency gained by utilizing a thinmembrane.

By “crossover” is meant material transfer, e.g., one or more componentsof a positively charged electrolyte that originates in the first tank ofa system becoming disposed in a negatively charged electrolyte thatoriginates in the second tank of a system. Crossover can give rise toundesired operational issues, e.g., local solid formation and in turnflow clogging; local parasitic reactions that can result in gasgeneration or pH change; long term loss of material and capacitydecrease; or cell electrical shorting.

Porous separators in the form of porous membranes may be non-conductivemembranes, which allow charge transfer between two electrodes via openchannels filled with conductive electrolyte. Porous membranes arepermeable to liquid or gaseous chemicals. This permeability increasesthe probability of active materials passing through porous membrane fromone electrode to another causing cross-contamination and/or reduction incell energy efficiency. The degree of this cross-contamination dependson, among other features, the size (the effective diameter and channellength), and character (e.g., surface characteristics) of the pores, thenature of the electrolyte and its active material, and the degree ofwetting between the pores and the electrolyte.

Porous membranes may also be ion-exchange membranes, which are sometimesreferred to as polymer electrolyte membranes (PEM) or ion conductivemembranes (ICM). The membranes according to the present disclosure cancomprise any suitable polymer, typically an ion exchange resin and, thusbe a polymeric anion exchange membrane, polymeric cation exchangemembrane, membrane composite of polymers with organic or inorganiccomponents, or a combination thereof. The mobile phase of such amembrane can comprise, and/or is responsible for the primary orpreferential transport (during operation of the battery) of at least onemono-, di-, tri-, or higher valent cation and/or mono-, di-, tri-, orhigher valent anion, other than protons or hydroxide ions.

Additionally, substantially non-fluorinated membranes that are modifiedwith sulfonic acid groups (or cation exchanged sulfonate groups) canalso be used. Such membranes include those with substantially aromaticbackbones, e.g., polystyrene, polyphenylene, bi-phenyl sulfone (BPSH),or thermoplastics such as polyetherketones or polyethersulfones.Examples of porous ion-exchange membranes include Nafion®.

Battery-separator style porous membranes can also be used. Because theycontain no inherent ionic conduction capability, such membranes may beimpregnated with additives or surface treatments in order to function.These membranes are typically comprised of a mixture of a polymer and aninorganic filler, and have open porosity. Suitable polymers includethose chemically compatible with the electrolytes of the presentlydescribed batteries, including high density polyethylene, polypropylene,polyvinylidene difluoride (PVDF), or polytetrafluoroethylene (PTFE).Suitable inorganic fillers include silicon carbide matrix material,titanium dioxide, silicon dioxide, zinc phosphide, and ceria. Themembrane can be supported internally with a substantially non-ionomericstructure, including mesh structures such as are known for this purposein the art. It should be understood that a membrane can comprisemultiple layers; a membrane can also be a single-layer membrane.

The disclosed methods are flexible in their utility with a range ofactive materials, such as redox couples, for use in the electrolytes.Suitable redox couples include those couples comprising a metal ormetalloid of Groups 2-16, including the lanthanide and actinideelements; for example, including those where the redox couple comprisesAl, As, Ca, Ce, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sb, Se, Si, Sn, Ti, V,W, Zn, or Zr, including coordination compounds of the same. In variousaspect of the present disclosure, the active materials may be solid,liquid, or gas, and may be in solutions, slurries, suspensions, ordispersions. In some aspects, the electrolyte may be aqueous ornon-aqueous electrolyte solutions. The electrolyte may further comprisebuffering materials, a supporting electrolyte, water misciblesolvent(s), mobile ions, viscosity modifiers, wetting agents, and othercomponents known to those skilled in the art. The electrolyte may alsocomprise impurities and unwanted byproducts that may be removed by asubflow structure, such as a balancing cell. Electrolytes with activematerials can be stored in a tank, in a container open to theatmosphere, or simply vented to the atmosphere.

As shown, a flow battery can also include one or more instruments 111,111 a, and 111 b, such as monitors, sensors, or processors, whetherinline or not inline. Without being bound to any particularconfiguration, a flow battery can include an instrument positioned so asto monitor a condition of an electrolyte that has entered or left theelectrochemical cell but is also in fluid isolation from the remainderof the dynamic fluidic network and the main electrolyte source.

A flow battery can also include one or more of instruments 119, 119 a,and 119 b, such as monitors, sensors, or processors, whether inline ornot inline. The instruments can be used to determine a characteristic ofactive material within the flow battery.

By reference to non-limiting FIG. 2 , instrument 111 can be used tomonitor electrolyte that has left electrochemical cell 131. Instrument111 a can be used to monitor electrolyte that is in a fluidic train influid isolation (e.g., when valves 135 and 125 are closed) from tank101. Instrument 111 b can be used to monitor fluid that is transportedfrom tank 101 to electrochemical cell 131.

Similarly, instrument 119 can be used to monitor electrolyte that hasleft electrochemical cell 131. Instrument 119 a can be used to monitorelectrolyte that is in a fluidic train in fluid isolation (e.g., whenvalves 133 and 129 are closed) from tank 121. Instrument 119 b can beused to monitor electrolyte that is transported from tank 121 toelectrochemical cell 131.

FIG. 5 provides a view of the exemplary flow battery of the presentdisclosure shown in FIG. 2 with additional instruments shown. In FIG. 5, an exemplary first fluidic train 137 is shown by a dashed line. Thefluidic train 137 with a first electrode region 139 shown by a heavydashed line constitute a diagnostic subflow structure of the presentdisclosure. The term “electrode region” refers to the region of flow andsubflow structures that carry electrolyte and is disposed within a givenhalf-cell of the electrochemical cell. One can determine the volume ofthe fluidic train as well as the volume of the electrode region. By wayof example, the instruments of a first dynamic fluidic network may bewithin the first fluidic train 137 (e.g., 111, 111 a, 111 b), outsidethe first fluidic train 137 (e.g., 111 c, 111 d), or both. Similarly,the instruments of a second dynamic fluidic network may be within thesecond fluidic train 147 (e.g., 119, 119 a, 119 b), outside the secondfluidic train 147 (e.g., 119 c, 119 d), or both.

As shown in FIGS. 2-10 , a flow battery can include one or more valves(123, 125, 127, 129, 133, 135, 145, 146, 155, and 156) or othermodalities that can be actuated to restrict and/or redirect electrolyteflow within the flow battery. As an example, a user could close valves135 and 125 so as to interrupt fluid communication from the largerdynamic fluidic network and include tank 101 to electrochemical cell131. Likewise, a user can close valves 129 and 133 so as to interruptfluid communication from the larger dynamic fluidic network and tank 121to electrochemical cell 131. Structures 141 a, 141 b, 141 c, and 141 dof FIGS. 2-7 represent additional flow and subflow structures, such as acounterflow structure, present in the dynamic fluidic network of theflow battery. The placements of these structures in these Figures arenot intended to show either relative or absolute placement thereof.Rather, they show conceptually that one or more flow and subflowstructures direct electrolyte to other aspects of the dynamic fluidicnetwork. For example, a flow battery can include flow structures withone or more valves or other modalities that can be actuated to permitelectrolyte flow, such as to relieve pressure buildup within the dynamicfluidic network or to relieve a voltage buildup within the dynamicfluidic network.

FIG. 3 provides a view of the exemplary flow battery of the presentdisclosure shown in FIG. 2 when the fluidic train is in a state wheretanks 101 and 121 are in fluid communication with the dynamic fluidicnetwork and the electrochemical cell 131. This state can be effected by,e.g., opening valves 125, 135, 129, and 133. Valves 123 and 127 can beclosed in this state, although this is not a requirement.

It should be understood that a flow battery can be changed from onestate to another in a manual fashion (e.g., via control of one or morevalves), but this can also be accomplished in an automated fashion. Asone non-limiting example, one or more processors can be configured toactuate one or more valves in an automated fashion so as to place afluidic train of a flow battery into a first state. One or moreprocessors can also be configured to actuate one or more valves in anautomated fashion so as to place a fluidic train of a flow battery intoa second state.

A fluidic train of a flow battery can be converted from one state toanother according to a predetermined schedule or to respond to differentcharacteristics that may be measured. As an example, the fluidic traincan be converted from a state (by reference to FIG. 3 ) in which bothtanks 101 and 121 are in fluid communication with the electrochemicalcell 131 (“state 1”) to a state (by reference to FIG. 4 ) in which tanks101 and 121 are in fluid isolation from the electrochemical cell 131(“state 2”). The conversion from state 1 to state 2 can be according toa predetermined schedule, e.g., every 6 hours, or as part of ameasurement-based control step that may affect flow and subflow. Theconversion from state 1 to state 2 can also be in response to one ormore signals received from an instrument of the flow battery, e.g., ifthe instrument detects a signal indicative that an electrolyte has a pHthat is below a certain threshold value and/or a temperature above acertain threshold value. Similarly, the battery can convert from state 2to state 1 when one or more received signals are indicative that acharacteristic of the electrolyte has returned to a predetermined valueor range. The present disclosure thus includes methods in which thefluidic train of a flow battery is converted between a first state and asecond state, the first state giving rise to a fluidic stream thatplaces electrolyte in one or more electrolyte sources in fluidcommunication with an electrochemical cell and the second state thatplaces the one or more electrolyte sources in fluid isolation from theelectrochemical cell.

As a non-limiting example, a user can charge the active material of theelectrolyte to 80% of the active material's maximum charge. If the user,however, does not desire to deliver full power immediately, the user canswitch from state 1 (FIG. 3 ) to state 2 (FIG. 4 ). In this way, thecharge state of the electrolyte within the relatively smaller state 2flow stream decreases as the active material in that electrolyte isdischarged, but the charge state of the active material contained withinthe relatively larger main electrolyte sources (which are in fluidisolation from the electrochemical cell) remains at 80%.

Similarly, (and again by reference to FIG. 3 and FIG. 4 ) a user canelect to maintain state 2 and charge the active material of theelectrolyte in the relatively smaller state 2 fluidic train andelectrode region while the main electrolyte sources are in fluidisolation from the electrochemical cell. In this manner, if a userdesires to maintain the active material in the electrolyte of the mainelectrolyte sources at a relatively lower state of charge as compared tothe active material of the electrolyte within the relatively smallerstate 2 fluidic train and electrode region, the user can do so. Inaddition, one tank (main electrolyte source) can remain in fluidcommunication with the electrochemical cell(s), while the other tank(main electrolyte source) is removed from fluid communication and thefluidic train associated with that other tank is placed into fluidcommunication with the electrochemical cell(s). This allows a firstelectrolyte in a first fluidic train and a first electrode region of theelectrochemical cell to cycle through its full SOC without changing theSOC of (i) the electrolyte in a first tank and remaining portions of afirst dynamic fluidic network and/or (ii) a second electrolyte goingthrough a second tank that remains in fluid communication with theelectrochemical cell. This is useful for, e.g., assessing performance ofone electrolyte or for mapping ORP to SOC through a full range withoutencountering or hitting limitations from the other electrolyte. Also asdescribed herein, if one has to do maintenance on the system, thepresence of the fluidic train allows local draining of the portions ofthe battery, without having to drain one or more of the main electrolytesources (tanks).

As shown in FIG. 3 , instrument 111 can be placed so as to monitorelectrolyte leaving from the electrochemical cell 131 to the dynamicfluidic network and tank 101. Instrument 111 b can also be placed to asto monitor electrolyte that is leaving from tank 101 towardelectrochemical cell 131. Likewise, instrument 119 can be placed to asto monitor electrolyte leaving from the electrochemical cell 131 to thedynamic fluidic network and tank 121. Instrument 119 b can be placed soas to monitor electrolyte that is leaving from tank 121 towardelectrochemical cell 131.

Instrument 111 a can be placed so as to monitor electrolyte in thefluidic train and electrode region that is in fluid isolation from tank101. By reference to FIG. 3 , such a sensor can be placed, e.g.,proximate to valve 123. Similarly, instrument 119 a can be placed so asto monitor electrolyte in the fluidic train and electrode region that isin fluid isolation from tank 121. By reference to FIG. 3 , such a sensorcan be placed, e.g., proximate to valve 127.

A person skilled in the art would appreciate that in certain aspects thefirst fluidic train in state 1 may comprise a pump configured to removethe first electrolyte from the first electrode region, such as during ashutdown. Similarly, a person skilled in the art would appreciate thatin certain aspects the pump may also be configured to return the firstelectrolyte to the first electrode region, such as during a startup. Inlieu of such a pump (a hydraulic system), an electrode region may bedewetted (electrolyte removed from the region) by way of a pneumaticsystem using forced gas (air, inert gas, such as nitrogen). A dewettedelectrode region is described as “state 3” hereinbelow.

It should be understood that FIG. 3 is illustrative only and that thepositions (absolute and relative) of the various elements within thatfigure need not be exactly as shown in the figure. For example, as shownin FIG. 6 , which is an exemplary flow battery of the presentdisclosure, valve 135 and valve 125 can be placed such that when theyare closed (and valve 123 is open), a different fluidic train is formedwhereby tank 101 is in fluid isolation from electrochemical cell 131 butelectrolyte that exits tank 101 traverses a dynamic fluidic network byway of its fluidic train and then re-enters tank 101 without alsopassing through electrochemical cell 131. FIG. 6 is representative only,and is not necessarily to scale, and does not show all flow, subflow, orother structures, but rather shows representative structures, whichserve to illustrate one potential setup of the flow battery as a whole

Likewise (and as shown in FIG. 6 ), valve 133 and valve 129 can beplaced such that when they are closed (and valve 127 is open), adifferent fluidic train is formed whereby tank 121 is in fluid isolationfrom electrochemical cell 131 but electrolyte that exits tank 121traverses a dynamic fluidic network by way of its fluidic train and thenre-enters tank 121 without also passing through electrochemical cell131.

FIG. 4 provides a view of the exemplary flow battery of the presentdisclosure shown in FIG. 2 in a state where tank 101 is not in fluidcommunication with electrochemical cell 131. This state can be effectedby closing valves 125 and 135; valve 123 can be open in this state. Thisstate defines a subflow structure including a fluidic train in which theelectrochemical cell 131 is not in fluid communication with tank 101. Inthis way, a user can assess a condition of the electrolyte in a portionof the flow battery without that electrolyte being returned to thelarger dynamic fluidic network and tank 101. As shown in FIG. 4 , a flowbattery can be placed in a state in which tank 121 is not in fluidcommunication with electrochemical cell 131. In such a state, valves 133and 129 are closed, while valve 127 can be open. A flow battery can bein a state in which either one or both of tanks 101 and 121 is in fluidisolation from electrochemical cell 131. A person skilled in the artwould appreciate that in certain aspects the first fluidic train maycomprise a pump configured to remove the first electrolyte from thefirst electrode region, such as during a shutdown. Similarly, a personskilled in the art would appreciate that in certain aspects the pump mayalso be configured to return the first electrolyte to the firstelectrode region, such as during a startup.

When a fluidic train is in state 2 (by reference to FIG. 4 ), thefluidic train may comprise (i) one or more instruments configured todetermine a characteristic of the respective electrolyte disposed withinthe respective sampling segment, (ii) one or more instruments configuredto determine a characteristic of respective electrolyte that is notdisposed within the respective sampling segment, or both (i) and (ii).By way of example, the first sampling segment may be coterminous withinstrument 111 a, which is configured to determine a characteristic ofthe first electrolyte disposed within the first sampling segment, andinstrument 111 is configured to determine a characteristic of firstelectrolyte that is not disposed within the first sampling segment. Byway of another example, the second sampling segment may be coterminouswith instrument 119, which is configured to determine a characteristicof the second electrolyte disposed within the first sampling segment,with no instrument configured to determine a characteristic of thesecond electrolyte that is not disposed within the second samplingsegment. In certain aspects, the flow battery of the present disclosuremay be configured to effect an action in response to a determinedcharacteristic of first electrolyte that is in fluid communication withthe first electrode region while the first fluidic train is in thesecond state. In certain aspects, exemplary characteristics includepressure, conductivity, color, temperature, turbidity, viscosity,ground-reference potential, density, concentration, water activity,oxidation-reduction potential (ORP), pH, state of charge, andcombinations thereof.

A non-limiting exemplary operation will be described, by reference toFIG. 2 . During normal operation, valve 125 is open, and pump 103effects transport of a first electrolyte from tank 101 through a firstdynamic fluidic network to electrode 107 within electrochemical cell131. Instrument 111 b can monitor a condition of the first electrolyte,including its active material. Similarly, pump 113 effects transport ofa second electrolyte from tank 121 into the first dynamic fluidicnetwork and to electrode 117 of electrochemical cell 131.

Ion exchange takes place at separator 109, while the two electrolytescirculate through their respective electrode regions of their respectivedynamic fluidic networks. Electric current that accompanies the ionexchange then powers load 140. Alternatively, load 140 can provide anelectric current to electrodes 107 and 117 so as to charge the flowbattery.

The first electrolyte (that was transported to the electrochemical cell131 by pump 103) then exits the electrochemical cell 131 in thedirection of valve 135. Instrument 111 can monitor a condition of thefirst electrolyte, including its active material, that is leaving theelectrochemical cell 131. If valve 135 is open, the first electrolyte isreturned to tank 101 by way of the first dynamic fluidic network.

During normal operation, valve 129 can be open, and pump 113 effectstransport of a second electrolyte from tank 121 into a second dynamicfluidic network and to electrode 117, within electrochemical cell 131.Instrument 119 can monitor a condition of the second electrolyte,including its active material. The second electrolyte (that wastransported to the electrochemical cell 131 by pump 113) then exits theelectrochemical cell 131 in the direction of valve 133. Instrument 119can monitor a condition of the second electrolyte, including its activematerial, that is leaving the electrochemical cell 131. If valve 133 isopen, the second electrolyte is returned by way of the second dynamicfluidic network to tank 101.

A user, however, can close certain valves so as to allow for flowbattery diagnostics/maintenance without needing to draw and returnelectrolyte from tanks 101 and 121. As an example, a user can closevalves 135 and 125 and open valve 123. In such a configuration, thefirst electrolyte can circulate within a subflow structure that includesthe electrochemical cell but does not include the remainder of the firstdynamic fluidic network and tank 101. This in turn allows a user toperform diagnostics on the electrochemical cell 131 without involvingelectrolyte actively drawn from tank 101. Such diagnostics can beperformed by, e.g., sensor 111, sensor, 111 a, and/or sensor 111 b. Thiscan also allow a user to operate the flow battery (for a time) withoutinvolving electrolyte actively drawn from tank 101, which in turn allowsthe user to perform maintenance on the tank 101 while the system isoperating. Conversely, by fluidically isolating the tank 101, a user canperform maintenance on the electrochemical cell 131 without having todrain the tank 101 or the portions of the dynamic fluidic network, asthe tank 101 will be in fluid isolation from the electrochemical cell131.

It should be understood that a flow battery can be operated when in thestate shown in FIG. 4 . In such a state, one or both of tanks 101 and121 are in fluid isolation from electrochemical cell 131. In thismanner, a flow battery can be operated without one or more mainelectrolyte sources with a first electrolyte being in fluidcommunication with the electrochemical cell. In this way, an operatorcan perform diagnostics on one or more tanks or regions within thedynamic fluid network while the system continues to operate.

By reference to FIG. 5 , the first electrode region 139 is the region offlow and subflow structures that is within the side of electrochemicalcell 131 through which the first electrolyte passes. One can alsodetermine the enclosed volume of the first electrode region 139 as wellas the enclosed volume of the first fluidic train 137. In some aspects,the first fluidic train 137 is defined as the subflow structure of thefirst dynamic fluidic network that carries electrolyte and that issuperposed by the electrode. One can compare the combined enclosedvolume of the first fluidic train 137 and the first electrode region 139(which combined can be termed a first diagnostic subflow structureenclosed volume) to the enclosed volume of the first tank 101 or to thefirst dynamic fluidic network without the first fluidic train 137 andfirst electrode region 139. In certain aspects, the combined enclosedvolume of the first fluidic train 137 and the first electrode region 139can define an enclosed volume that is less than or equal to the enclosedvolume of the first tank 101, e.g., by a factor of 0.9 (i.e., that thevolume of the first fluidic train 137 and the first electrode region 139is 90% of the volume of the first tank 101), 0.8, 0.7, 0.6, 0.5, 0.4,0.3, 0.2, 0.1, 0.05, 0.01, or even 0.001, along with all intermediatevalues and ranges. Alternatively, a ratio of the enclosed volume of thefirst fluidic train and the enclosed volume of the first mainelectrolyte source is from about 1:100,000 to about 1:1, e.g., fromabout 1:100,000 to about 1:1, from about 1:50,000 to about 1:1, fromabout 1:25,000 to about 1:1, from about 1:15,000 to about 1:1, fromabout 1:5,000 to about 1:1, from about 1:1,000 to about 1:1, from about1:500 to about 1:1, from about 1:250 to about 1:1, from about 1:100 toabout 1:1, from about 1:50 to about 1:1, from about 1:10 to about 1:1,from about 1:5 to about 1:1.

In certain aspects, a ratio of the enclosed volume of the firstelectrode region and the enclosed volume of the first fluidic train isfrom about 1:1000 to about 1:1, e.g., from about 1:1000 to about 1:1,from about 1:750 to about 1:1, from about 1:500 to about 1:1, from about1:250 to about 1:1, from about 1:100 to about 1:1, from about 1:50 toabout 1:1, from about 1:25 to about 1:1, from about 1:10 to about 1:1,or from about 1:5 to about 1:1. In one aspect, the ratio of the enclosedvolume of the first electrode region and the enclosed volume of thefirst fluidic train is from about 0.95:1.05 to about 0.90:1.10.

As shown in FIG. 5 , a second fluidic train 147 is shown by a dashedline, with a second electrode region 149 shown by a heavy dashed line.The second electrode region 149 is the region of flow and subflowstructures that is within the side of electrochemical cell 131 throughwhich the second electrolyte passes. One can determine the enclosedvolume of the second fluidic train 147 as well as the enclosed volume ofthe second electrode region 149. One can compare the combined enclosedvolume (which can be termed a second diagnostic subflow structureenclosed volume) of the second fluidic train 147 and the secondelectrode region 149 to the enclosed volume of the second tank 121. Asdescribed elsewhere, the combined enclosed volume of the second fluidictrain 147 and the second electrode region 149 can define an enclosedvolume that is less than the enclosed volume of the second tank 121,e.g., by a factor of 0.9 (i.e., that the enclosed volume of the secondfluidic train 147 and the second electrode region 149 is 90% of theenclosed volume of the second tank 121), 0.8, 0.7, 0.6, 0.5, 0.4, 0.3,0.2, 0.1, 0.05, 0.01, or even 0.001, along with all intermediate valuesand ranges. Alternatively, a ratio of the enclosed volume of the secondfluidic train and the enclosed volume of the second main electrolytesource is from about 1:100,000 to about 1:1, e.g., from about 1:100,000to about 1:1, from about 1:50,000 to about 1:1, from about 1:25,000 toabout 1:1, from about 1:15,000 to about 1:1, from about 1:5,000 to about1:1, from about 1:1,000 to about 1:1, from about 1:500 to about 1:1,from about 1:250 to about 1:1, from about 1:100 to about 1:1, from about1:50 to about 1:1, from about 1:10 to about 1:1, from about 1:5 to about1:1.

In certain aspects, a ratio of the enclosed volume of the secondelectrode region and the enclosed volume of the second fluidic train isfrom about 1:1000 to about 1:1, e.g., from about 1:1000 to about 1:1,from about 1:750 to about 1:1, from about 1:500 to about 1:1, from about1:250 to about 1:1, from about 1:100 to about 1:1, from about 1:50 toabout 1:1, from about 1:25 to about 1:1, from about 1:10 to about 1:1,or from about 1:5 to about 1:1. In one aspect, the ratio of the enclosedvolume of the second electrode region and the enclosed volume of thesecond fluidic train is from about 0.95:1.05 to about 0.90:1.10.

The sum of a fluidic train enclosed volume and an electrode regionenclosed volume is therefore an enclosed volume of a particulardiagnostic subflow structure.

By reference to non-limiting FIG. 5 , one sampling segment is thelocation within the first fluidic train 137 that is superposed byinstrument 111. Another sampling segment of the first fluidic train 137is the location within the first fluidic train that is superposed byinstrument 111 a.

FIG. 7 provides a view of an exemplary flow battery of the presentdisclosure with a fluidic train in a third state where an electroderegion is in fluid isolation from the remainder of its respectivedynamic fluidic network and tank. For example, this state can beeffected by closing valves 145 and 155; valves 123, 125, and/or 135 canbe open in this state. The first electrode region is thereby in fluidisolation from the remainder of the first dynamic fluidic network,including the first fluidic train, and tank 101. In this way, a user cande-energize the electrochemical cell 131 without affecting the flowbattery or flow battery system as a whole. As shown in FIG. 7 , a flowbattery can be placed in a state in which the second electrode regionwithin flow plate 115 is in fluid isolation from the remainder of thesecond dynamic fluidic network, including the second fluidic train, andtank 121. In such a state, valves 146 and 156 are closed and valves 127,129, and/or 133 can be open. A flow battery can be in a state in whicheither one or both of electrode regions 139 and 149 is in fluidisolation from remainder of the battery. Also as described herein, ifone has to do maintenance on the system, the presence of the fluidictrain in the third state also allows local draining of the electroderegion, without having to drain other portions of the flow battery. FIG.7 is representative only, is not necessarily to scale, and does not showall flow, subflow, or other structures, but rather shows representativestructures, which serve to illustrate one potential setup of the flowbattery as a whole.

It should be understood that the attached figures depict specific butnon-limiting aspects of a flow battery. Accordingly, flow batteries andflow battery systems according to the present disclosure can includesome or even all of the aspects of the flow batteries depicted in FIGS.1-12 .

In some cases, a user may desire to provide higher charge or dischargevoltages than available from a single battery. In such cases, and incertain aspects then, several batteries are connected in series suchthat the voltage of each electrochemical cell is additive. Anelectrically conductive, but non-porous material (e.g., a bipolar plateassembly) can be employed to connect adjacent electrochemical cells in abipolar stack, which allows for electron transport but prevents fluid orgas transport between adjacent electrochemical cells. The positiveelectrode compartments and negative electrode compartments of individualelectrochemical cells are suitably fluidically connected via commonpositive and negative fluid manifolds in the stack. In this way,individual electrochemical cells can be stacked in series to yield adesired operational voltage. Multiple electrochemical cells electricallyconnected to each other in series are referred to as a “stack” in thisdisclosure.

In some cases, a user may desire to provide a better current performancethan available from a single battery. In such cases, and in certainaspects, several batteries may be connected in parallel.

In additional aspects, the cells, cell stacks, or batteries can beincorporated into larger energy storage and generation systems, suitablyincluding piping and controls useful for operation of these large units.Piping, control, and other equipment suitable for such systems are knownin the art, and include, for example, piping and pumps in fluidcommunication with one or more components of the flow battery, such asfor moving electrolytes into and out of the electrochemical cells andmain electrolyte sources, utilizing storage tanks for holding chargedand discharged electrolytes. The energy storage and generation systemsthat include the flow batteries described by the present disclosure caninclude further electrolyte circulation streams, which may comprise oneor more valves, one or more pumps, and optionally a pressure equalizingline. The energy storage and generation systems that include the flowbatteries of this disclosure can also include an operation managementsystem. The operation management system may be any suitable controllerdevice, such as a computer or microprocessor, and may contain logiccircuitry that sets operation of any of the various valves, pumps, flowand subflow structures, and the like.

In some aspects, a flow battery system comprises a flow battery(including main electrolyte source(s), electrochemical cell(s), and adynamic fluidic network system); storage tanks and piping for containingand transporting the electrolytes to and from the flow battery; controlhardware and software (which may include safety systems); and a powerconditioning unit. The flow battery's electrochemical cell(s)accomplishes the conversion of charging and discharging cycles anddetermines the peak power of energy storage system, which power may insome aspects be in the kW range.

The (main) electrolyte sources and storage tanks contain theelectrolytes with the positive and negative active materials. Theelectrolyte source volumes and the concentrations of active materialsdetermine the quantity of energy stored in the flow battery, which maybe measured in kWh. The flow battery of the present disclosure comprisesa first main electrolyte source configured to contain a positiveelectrolyte and a second main electrolyte source configured to contain anegative electrolyte. In certain aspects, it is contemplated that theremay be additional electrolyte sources containing positive or negativeelectrolyte.

Control software, hardware, and optional safety systems suitably includeinstruments, mitigation equipment and other electronic/hardware controlsand safeguards to ensure safe, autonomous, and efficient operation ofthe flow battery and flow battery system. As described herein, these maybe placed in various locations throughout the dynamic fluidic networksystem, or other locations of the flow battery system. Such controlsoftware, hardware, and optional safety systems are known to those ofordinary skill in the art. Exemplary hardware may include a controlcenter with monitors displaying real-time information from theinstruments, and configured with an optional alarm or detection system,to identify when a certain property exceeded acceptable control limits.

A power conditioning unit may be used at the front end of the flowbattery system to convert incoming and outgoing power to a voltage andcurrent that is optimal for the flow battery system or the application.For the example of a flow battery connected to an electrical grid, in acharging cycle the power conditioning unit would convert incoming ACelectricity into DC electricity at an appropriate voltage and currentfor the electrochemical cell(s). In a discharging cycle, theelectrochemical cells(s) produce DC electrical power and the powerconditioning unit converts to AC electrical power at the appropriatevoltage and frequency for grid applications.

Referring again to FIG. 1 , a subregion of a dynamic fluid network isshown in which electrolyte is delivered to half-cells of twoelectrochemical cell(s). In this depiction, a subflow structure 4 havingV₄, A₄ delivers electrolyte to subflow structures 6, 7 branched inparallel to deliver the electrolyte to multiple cells, and thesestructures have V₆, A₆ and V₇, A₇, respectively.

These subflow structures feed the electrolyte to manifolds on a surfaceof a bipolar plate assembly (BPPA) or a surface of a monopolar plateassembly (MPPA), which “n” manifolds have their own volumes (“V_(n)”)and cross-sectional areas (“A_(n)”), and these supply electrolyte toflow channels in the corresponding surface of the flow plate, whetherBPPA or MPPA.

A BPPA has a frame and an inner plate on positive and negative sides ofthe BPPA. Similarly, a MPPA has a frame and an inner plate on one side.The frame and inner plate may be made of different materials that arejoined together, are substantially coplanar, and form an integral,unitary structure. Exemplary BPPA and MPPA structures are depicted inFIG. 11 with exemplary flow structures for the BPPA depicted in FIG. 12. Shown are structures comprising an integrated assembly of a frame 10and a structure (e.g., an inner plate) within the frame (flow andsubflow structures comprising a single overall flow structure in a MPPAor on either side of a BPPA). The frame 10 has various flow and subflowstructures of the dynamic fluidic network system, including inlet andoutlet conduits 11 for conveying electrolytes through multipleelectrochemical cells in a stack, and an inlet (source) manifold 12 oneach side of the bipolar plate (a single side of a monopolar plate) todeliver first and second electrolytes to their corresponding inlet(source) flow structures 14 of the inner plate, and outlet (drain)manifolds 13 on each side of the bipolar plate (a single side of amonopolar plate) to drain reacted electrolyte from outlet (drain) flowstructures 14 of the inner plate. Each side of the bipolar plate (andthe single side of a monopolar plate) has inlet (source) manifolds 12 onone edge and outlet (drain) manifolds 13 on a second edge. The inlet andoutlet conduits 11 communicate fluidically with their respective inletand outlet manifolds 12, 13, which fluidically communicate with theirrespective inlet and outlet flow structures 14 of the inner plate. Insome aspects, the inlet and outlet manifolds 12, 13 may have holes thatcommunicate fluidically with one or more inlet and outlet flowstructures of the inner plate, respectively.

The design and orientation of these flow structures and subflowstructures may be selected to achieve various desired functions,including improved electrolyte flow. FIGS. 11 and 12 are not necessaryto scale, and do not show all flow, subflow, or other structures, butrather shows representative structures, which serve to illustrate onepotential setup of a plate assembly of the flow battery. The geometriesand other architectural features of plate structures shown in FIGS. 11and 12 are not limiting, and geometrical forms, and placing and spacingof components, may be selected to achieve particular objectives.

Each of “n” flow structures and subflow structures leading to and withinthe BPPA or MPPA has its own volume (“V_(n)”) and cross-sectional area(“A_(n)”), as depicted in FIGS. 11 and 12 . The typical relationship ofthese inlet (source) structures is: V₄>V₆ or V₇>V₁₁>V₁₂>>V₁₄ with thesame progression and relationships for the A_(n) values. Although notfully shown in FIGS. 11 and 12 , these inlet (source) structures willhave correlative outlet (drain) structures, typically on an oppositeedge of a BPPA (or MPPA), having V_(n) and A_(n) values with aprogression and relationships that will generally be the reverse ofthose for the correlative inlet structures, in that those V and A valueswill go from smallest to progressively larger.

BPPAs and MPPAs may have flow structures with subflow structures such asinlet and outlet conduits, inlet and outlet manifolds, and inlet andoutlet flow structures serving each side of a BPPA (or the single sideof an MPPA). The design of these flow structures and their subflowstructures may vary depending on the needs of a particular flow batteryand flow battery system and even as between different types ofelectrolyte solutions. For example, the V_(n) and A_(n) values for amanifold as well as its shape and length may be designed for flowdynamic results and also to help manage shunt currents in a battery orstack by making the manifold structure itself more electricallyresistive. In a two-electrolyte flow battery where positive and negativeelectrolytes are different, one electrolyte may tend to be moresusceptible to shunt currents than the other electrolyte, so in thisrespect, manifold design for one side of a bipolar plate may be longerand narrower than a manifold on the other side of the bipolar plate.This may be applied to the inlet, outlet, or both manifolds. Flowcharacteristics of negative and positive electrolytes may also vary suchthat design of other subflow structures of the plate's flow structuremay be different.

Each “n” inlet and outlet manifold has values for V_(n), A_(n), a lengthL_(n), and a path P_(n), such that V_(n), A_(n), L_(n), and P_(n) definea shape (path) of the manifold within a portion of the BPPA or MPPA. Oneor more of V_(n), A_(n), L_(n), and P_(n) values may be the same ordifferent between inlet and outlet manifolds on the same side of theBPPA or MPPA. One or more of V_(n), A_(n), L_(n), and P_(n) values maybe the same or different between inlet and outlet manifolds on differentsides of the BPPA. A pathway may be elongated, such that the length ofthe manifold is extended beyond that necessary to link a respectiveconduit with inner plate flow structures, or to link a respectiveconduit with a structure, such as a plenum, that supplies electrolyte toinner plate flow structures. An example of an elongated pathway is an“s-curve” manifold configuration, which is understood to comprise asubflow structure that crosses the majority of the width of the plateassembly at least twice making >90 degree turns before deliveringelectrolytes to the corresponding inner plate subflow structure (seebelow). By way of example, FIG. 12 depicts the inlet and outletmanifolds 15, 16 for a first electrolyte having an elongated pathway,here depicted as a more circuitous “s-curve” or serpentine pathway, thanthe inlet and outlet manifolds 12, 13 for a second electrolyte. Hence,the shunt current control subflow structures (such as for shunt currentmitigation and/or management), of the dynamic fluid network may comprisethe manifold(s), conduits(s), and/or other subflow structures. Negativeand positive flow structure designs may share many commoncharacteristics in aspects of the disclosure. In aspects, the innerplate may be made of a conductive material, or may be a non-conductivematerial that is infused with conductive material, or is overlain byconductive material affixed thereto.

Each side of a BPPA and MPPA has an inner plate with a subflowstructure. The inner plate subflow structures may have a variety ofdifferent patterns, on either side of a BPPA or MPPA, or may vary fordifferent needs. The inner plate subflow structures comprise a pluralityof inlet and outlet flow structures 14 that may be of any configurationor pattern known in the art, including use of reticulated flow andsubflow structures. For example, the inner plate's subflow structure mayhave a first inlet flow structure, a second inlet flow structure, athird inlet flow structure, and a fourth inlet flow structure, which mayor may not be structurally or fluidically connected to each other withinthe inner plate.

Similar to the inlet and outlet manifolds, each “n” inlet and outletflow structure of a BPPA or MPPA inner plate has values for V_(n),A_(n), a length L_(n), and a path P_(n), such that V_(n), A_(n), L_(n),and P_(n) define a shape, and path, of the inner plate flow structures,and collectively, a pattern. The V_(n), A_(n), L_(n), and P_(n) valuesfor inlet and outlet flow structures in the inner plate are independentof each other, and may be the same or different. The corresponding innerplate subflow structures of each side of a BPPA may have the same ordifferent patterns or configurations of inlet and/or outlet flowstructures. These differences between inner plate subflow structures maybe throughout the inner plate subflow structure or only withinsub-regions of the inner plate subflow structures. Similarly, thecorresponding inner plate subflow structures of MPPAs with oppositepolarity may have the same or different patterns or configurations ofinlet and/or outlet flow channels.

A counterflow structure is associated with instruments (monitors,sensors, processors) that detect or measure conditions (at least onecharacteristic) of the electrolyte in the flow battery, which mayrequire treatment of all or a portion of the electrolyte in the flowbattery, such as with a treatment subflow structure. A non-limitingexample of a treatment subflow structure is a rebalancing subflowstructure. Once such need is ascertained, the volume of electrolyte tobe treated may be measured or calculated, and sufficient electrolyte toachieve adequate rebalancing may be conveyed to a balancing cell,treated, and reintroduced into the battery. The volume to be treated maybe all or a portion of the total volume of electrolyte in the system,such as that of the electrochemical cell(s). Given this understanding, aperson of ordinary skill in the art would be able to selectively placeand operate any subflow structures and valves to define the volume to berebalanced. The counterflow structure may operate such that the flow iscounter to or concurrent with the typical flow of electrolyte with theflow battery, such as from a main electrolyte source to an electroderegion and back to the main electrolyte source. A counterflow structuremay also be associated with a balancing cell, as described below.

FIG. 8 depicts an exemplary flow battery of the present disclosure witha counterflow structure 142 of the dynamic fluidic network. FIG. 8 isrepresentative only, is not necessarily to scale, and does not show allflow, subflow, or other structures, but rather shows representativestructures, which serve to illustrate one potential setup of the flowbattery as a whole. The counterflow structure may be configured tofluidically communicate with the remainder of the dynamic fluidicnetwork, when the electrochemical cell(s) are isolated with valves 125and 135 closed. As shown, the counterflow structure 142 fluidicallycomprises a pump 143 and a balancing cell 144, and as further shown,conveys a negative electrolyte to the balancing cell for rebalancing.The counterflow structure 142 then reintroduces the treated negativeelectrolyte into the remainder of the dynamic fluidic network, excludingthe isolated electrochemical cell 131. When the charge of theelectrolyte reaches a predetermined level, valves 125 and 135 areopened, placing the electrochemical cell 131 in fluid communication withthe remainder of the flow battery. Exemplary balancing cells arediscussed in U.S. Patent Application Publication Nos. 2016/0233531,2016/0308234, 2016/0308235, 2017/0317363, 2018/0277868, and2020/0313212, which are incorporated herein by reference.

In another non-limiting example of a flow battery of the presentdisclosure with a counterflow structure 142 of the dynamic fluidicnetwork, described by reference to FIG. 9 , instrument 111 can monitorthe characteristics of the electrolyte leaving electrochemical cell 131.For example, when the charge of the electrolyte reaches a predeterminedlevel, valves 125 and 135 are closed, isolating the electrochemical cell131 from the remainder of the battery. Pump 143 effects transport of theelectrolyte from the electrochemical cell 131 and through the balancingcell 144 and back to the electrochemical cell 131. When instrument 111,which continues to monitor the characteristics of the electrolyte,determines that the charge has reached a predetermined level, valves 125and 135 are open such that electrochemical cell 131 is in fluidcommunication the remainder of the battery. FIG. 9 is representativeonly, is not necessarily to scale, and does not show all flow, subflow,or other structures, but rather shows representative structures, whichserve to illustrate one potential setup of the flow battery as a whole.

A single counterflow structure and balancing cell are depicted in FIGS.8 and 9 , but a second electrolyte may also be rebalanced when needed.Two electrolytes may be treated simultaneously or sequentially in asingle balancing cell, or optionally, a second balancing cell may beincluded for a second electrolyte. Two electrolytes may be balancedindependently of each other. In addition, the condition orcharacteristic being monitored may be that of an electrolyte within adiagnostic subflow structure, outside a diagnostic subflow structure, orboth. One or more counterflow structures may be incorporated into anybattery or system configuration. Alternatively, flow and subflowstructures in lieu of, or in addition to, a subflow structure may alsobe used, as further described herein.

In some aspects, the flow structures and subflow structures may beisolated flow structures and subflow structures. The isolated flowstructures and subflow structures are in fluid isolation from theremainder of the dynamic fluidic network without affecting the operationof the flow battery. For example, counterflow structures, diagnosticsubflow structures, and treatment subflow structures may be isolatedstructures and subflow structures. By way of example, an isolatedtreatment subflow structure can treat the electrolyte within the subflowstructure while not affecting the operation of the flow battery.

The flow batteries and flow battery storage systems of the presentdisclosure are, in some aspects, suited to sustained charge or dischargecycles of several hour durations. As such, the batteries and systems ofthe present disclosure may be used to smooth energy supply/demandprofiles and provide a mechanism for stabilizing intermittent powergeneration assets (e.g., from renewable energy sources). It should beappreciated, then, that various aspects of the present disclosureinclude those electrical energy storage applications where such longcharge or discharge durations are valuable. For example, non-limitingexamples of such applications include those where systems of the presentdisclosure are connected to an electrical grid include, so as to allowrenewables integration, peak load shifting, grid firming, baseload powergeneration consumption, energy arbitrage, transmission and distributionasset deferral, weak grid support, and/or frequency regulation.Electrochemical cells, batteries, or stacks according to the presentdisclosure may be used to provide stable power for applications that arenot connected to a grid, or a micro-grid, for example as power sourcesfor remote camps, forward operating bases, off-grid telecommunications,or remote sensors.

It should be appreciated that, while the various aspects describedherein are described in terms of flow batteries and flow batterysystems, the same strategies and design may also be employed withstationary (non-flow) electrochemical cells, batteries, or systems,including those where one or both half cells employ stationaryelectrolytes. Each of these aspects is considered within the scope ofthe present invention.

Aspects

The following Aspects are illustrative only and do not serve to limitthe scope of the present disclosure or the appended claims.

Aspect 1. A flow battery comprising: a dynamic fluidic network systemcomprising a first dynamic fluidic network and second fluidic network;wherein the flow battery has a first half and a second half, the firsthalf comprising (i) a first main electrolyte source configured tocontain a first electrolyte, (ii) a first electrode region configuredfor electronic communication with the first electrolyte, and (iii) thefirst dynamic fluidic network configured for fluid communication withthe first main electrolyte source and comprising the first electroderegion, a first fluidic train, and a first counterflow structure, thefirst fluidic train comprising a first sampling segment and the firstfluidic train being convertible between a first state and a secondstate, the first state placing the first main electrolyte source and thefirst dynamic fluidic network, outside the first fluidic train and firstelectrode region, into fluid communication with the first electroderegion, the second state placing the first main electrolyte source andthe first dynamic fluidic network, outside the first fluidic train andfirst electrode region, into fluid isolation from the first electroderegion and placing the first electrode region into fluid communicationwith the first sampling segment, the second half comprising (i) a secondmain electrolyte source configured to contain a second electrolyte,(ii), a second electrode region configured for electronic communicationwith the second electrolyte, and (iii) the second fluidic networkconfigured for fluid communication with the second main electrolytesource and comprising the second electrode region and a second fluidictrain, the second fluidic train configured to place the second mainelectrolyte source and second fluidic network, outside the secondfluidic train and second electrode region, into fluid communication withthe second electrode region.

Alternatively, in lieu of or in addition to the first counterflowstructure, the first dynamic fluidic network may have flow structuresselected from series subflow structures, parallel subflow structures,shunt current control subflow structures (such as for shunt currentmitigation and/or management), measurement subflow structures,diagnostic subflow structures, treatment (such as electrolyterebalancing) subflow structures, source subflow structures, reticulatedsubflow structures, drain subflow structures, and combinations thereof.The flow battery may be a redox flow battery. For clarity, the presenceof a counterflow structure does not preclude inclusion of any of theflow/subflow structures described herein.

Aspect 2. The flow battery of Aspect 1, wherein the first state of thefirst fluidic train also places the first sampling segment into fluidcommunication with at least one of (i) the first main electrolytesource, (ii) the first dynamic fluidic network, outside the firstfluidic train and first electrode region, and (iii) the first electroderegion.

Aspect 3. The flow battery of Aspect 1 or Aspect 2, wherein the firstfluidic train is convertible to a third state, the third state placingthe first electrode region into fluid isolation from the first dynamicfluidic network, outside the first electrode region.

Aspect 4. The flow battery of any one of Aspects 1 to 3, wherein thesecond fluidic train comprises a second sampling segment, the secondfluidic network is a dynamic fluidic network further comprising a secondcounterflow structure, and the second fluidic train is convertiblebetween a first state and a second state, the first state of the secondfluidic train placing the second main electrolyte source and the seconddynamic fluidic network, outside the second fluidic train and secondelectrode region, into fluid communication with the second electroderegion, the second state of the second fluidic train placing the secondmain electrolyte source and the second dynamic fluidic network, outsidethe second fluidic train and the second electrode region, into fluidisolation from the second electrode region and placing the secondelectrode region into fluid communication with the second samplingsegment.

Alternatively, in lieu of or in addition to the second counterflowstructure, the second dynamic fluidic network may have flow structuresselected from series subflow structures, parallel subflow structures,shunt current control subflow structures (such as for shunt currentmitigation and/or management), measurement subflow structures,diagnostic subflow structures, treatment (such as electrolyterebalancing) subflow structures, source subflow structures, reticulatedsubflow structures, drain subflow structures, and combinations thereof.For clarity, the presence of a counterflow structure does not precludeinclusion of any of the flow/subflow structures described herein.

Aspect 5. The flow battery of Aspect 4, wherein the first state of thesecond fluidic train also places the second sampling segment into fluidcommunication with at least one of (i) the second main electrolytesource, (ii) the second dynamic fluidic network, outside the secondfluidic train and second electrode region, and (iii) the secondelectrode region.

Aspect 6. The flow battery of Aspect 4 or Aspect 5, wherein the secondfluidic train is convertible to a third state, the third state placingthe second electrode region into fluid isolation from the second dynamicfluidic network, outside the second electrode region.

Aspect 7. The flow battery of any one of Aspects 1 to 6, wherein:

-   -   (a) (i) one or more instruments configured to determine a        characteristic of first electrolyte disposed within the first        sampling segment, (ii) one or more instruments configured to        determine a characteristic of first electrolyte that is not        disposed within the first sampling segment, or both (i) and (ii)        are located within the first fluidic train; or    -   (b) instruments configured to (i) determine a characteristic of        first electrolyte disposed within the first sampling        segment, (ii) determine a characteristic of first electrolyte        that is not disposed within the first sampling segment, or        both (i) and (ii), are located outside the first fluidic train;        or    -   (c) combinations of both (a) and (b).

Aspect 8. The flow battery of Aspect 7(a), or (b), or (c), wherein thecharacteristic of first electrolyte is selected from pressure,conductivity, color, temperature, turbidity, viscosity, ground-referencepotential, density, concentration, water activity, oxidation-reductionpotential, pH, state of charge, and combinations thereof.

Aspect 9. The flow battery of Aspect 7(a), or (b), or (c), wherein theinstruments comprise both (i) and (ii) and the characteristic determinedby (i) is the same as the characteristic determined by (ii).

Aspect 10. The flow battery of any one of Aspects 4 to 6, wherein:

-   -   (a) (i) one or more instruments configured to determine a        characteristic of second electrolyte disposed within the second        sampling segment, (ii) one or more instruments configured to        determine a characteristic of second electrolyte that is not        disposed within the second sampling segment, or both (i)        and (ii) are located within the second fluidic train; or    -   (b) instruments configured to: (i) determine a characteristic of        second electrolyte disposed within the second sampling        segment, (ii) determine a characteristic of second electrolyte        that is not disposed within the second sampling segment, or        both (i) and (ii), are located outside the second fluidic train;        or    -   (c) combinations of both (a) and (b).

Aspect 11. The flow battery of Aspect 10, wherein the characteristic ofsecond electrolyte is selected from pressure, conductivity, color,temperature, turbidity, viscosity, ground-reference potential, density,concentration, water activity, oxidation-reduction potential, pH, stateof charge, and combinations thereof.

Aspect 12. The flow battery of Aspect 10(a), or (b), or (c), wherein theinstruments comprise both (i) and (ii) and the characteristic determinedby (i) is the same as the characteristic determined by (ii).

Aspect 13. The flow battery of any one of Aspects 1 to 12, wherein thefirst electrode region has an enclosed volume, wherein the first fluidictrain in its second state has an enclosed volume, and wherein the ratioof the enclosed volume of the first electrode region and the enclosedvolume of the first fluidic train is from about 1:1000 to about 1:1,e.g., from about 1:1000 to about 1:1, from about 1:750 to about 1:1,from about 1:500 to about 1:1, from about 1:250 to about 1:1, from about1:100 to about 1:1, from about 1:50 to about 1:1, from about 1:25 toabout 1:1, from about 1:10 to about 1:1, or from about 1:5 to about 1:1.

Aspect 14. The flow battery of Aspect 13, wherein the ratio of theenclosed volume of the first electrode region and the enclosed volume ofthe first fluidic train is from about 0.95:1.05 to about 0.90:1.10.

Aspect 15. The flow battery of any one of Aspects 1 to 14, wherein thefirst electrolyte source has an enclosed volume, wherein the firstfluidic train in its second state has an enclosed volume, and whereinthe ratio of the enclosed volume of the first fluidic train and theenclosed volume of the first electrolyte source is from about 1:100,000to about 1:1, e.g., from about 1:100,000 to about 1:1, from about1:50,000 to about 1:1, from about 1:25,000 to about 1:1, from about1:15,000 to about 1:1, from about 1:5,000 to about 1:1, from about1:1,000 to about 1:1, from about 1:500 to about 1:1, from about 1:250 toabout 1:1, from about 1:100 to about 1:1, from about 1:50 to about 1:1,from about 1:10 to about 1:1, from about 1:5 to about 1:11.

Aspect 16. The flow battery of any one of Aspects 1 to 15, wherein thesecond electrode region has an enclosed volume, wherein the secondfluidic train in its second state has an enclosed volume, and whereinthe ratio of the enclosed volume of the second electrode region and theenclosed volume of the second fluidic train is from about 1:1000 toabout 1:1, e.g., from about 1:1000 to about 1:1, from about 1:750 toabout 1:1, from about 1:500 to about 1:1, from about 1:250 to about 1:1,from about 1:100 to about 1:1, from about 1:50 to about 1:1, from about1:25 to about 1:1, from about 1:10 to about 1:1, or from about 1:5 toabout 1:1.

Aspect 17. The flow battery of Aspect 16, wherein the ratio of theenclosed volume of the second electrode region and the enclosed volumeof the second fluidic train is from about 0.95:1.05 to about 0.90:1.10.

Aspect 18. The flow battery of any one of Aspects 1 to 17, wherein thesecond electrolyte source has an enclosed volume, wherein the secondfluidic train in its second state has an enclosed volume, and whereinthe ratio of the enclosed volume of the second fluidic train and theenclosed volume of the second electrolyte source is from about 1:100,000to about 1:1, e.g., from about 1:100,000 to about 1:1, from about1:50,000 to about 1:1, from about 1:25,000 to about 1:1, from about1:15,000 to about 1:1, from about 1:5,000 to about 1:1, from about1:1,000 to about 1:1, from about 1:500 to about 1:1, from about 1:250 toabout 1:1, from about 1:100 to about 1:1, from about 1:50 to about 1:1,from about 1:10 to about 1:1, from about 1:5 to about 1:11.

Aspect 19. The flow battery of any one of Aspects 1-18, wherein az-direction is defined as parallel to the force of gravity, and whereinan x-y plane, which is perpendicular to the z-direction at a givenz-value, intersects the first main electrolyte source and the firstelectrode region. For example, as shown in FIG. 10 , the z-direction isdefined as parallel to the force of gravity, g, and an x-y plane, whichis perpendicular to the z-direction at a given z-value, intersects thefirst main electrolyte source and the first electrode region. Inparticular, as shown in FIG. 10 , the x-y plane at a point z₁ intersectsthe first main electrolyte source 101 and the first electrode region 139at the source of the first electrode region. A person skilled in the artwould appreciate that an x-y plane, which is perpendicular to thez-direction at a given z-value, may intersect any or all of the mainelectrolyte sources and any or all of the electrode regions of the flowbattery.

Aspect 20. The flow battery of any one of Aspects 1 to 19, wherein thefirst fluidic train comprises either a pump or a pneumatic systemconfigured to clear first electrolyte from the first electrode region.

Aspect 21. The flow battery of claim 20, wherein the pump or pneumaticsystem is configured to clear first electrolyte from the first electroderegion when the first fluidic train is in its second state.

Aspect 22. The flow battery of any one of Aspects 1 to 21, wherein thesecond fluidic train comprises either a pump or a pneumatic systemconfigured to clear second electrolyte from the second electrode region.

Aspect 23. The flow battery of Aspect 22, wherein the pump or pneumaticsystem is configured to clear second electrolyte from the secondelectrode region when the second fluidic train is in its second state.

Aspect 24. The flow battery of any one of Aspects 1 to 23, wherein theflow battery is configured to effect an action in response to adetermined characteristic of first electrolyte that is in fluidcommunication with the first electrode region while the first fluidictrain is in its second state. For example, the redox flow battery can beconfigured to effect an action in response to one or more of a detectedpressure, conductivity, color, temperature, turbidity, viscosity,ground-reference potential, density, concentration, water activity,reduction potential, state of charge, and pH. Such actions can include,without limitation, adding first electrolyte, removing firstelectrolyte, increasing a state of charge and/or pH of the firstelectrolyte, or even decreasing a state of charge and/or pH of firstelectrolyte.

Aspect 25. The flow battery of any one of Aspects 1 to 24, wherein theflow battery is configured to effect an action in response to adetermined characteristic of second electrolyte that is in fluidcommunication with the second electrode region while the second fluidictrain is in its second state. For example, the redox flow battery can beconfigured to effect an action in response to one or more of a detectedpressure, conductivity, color, temperature, turbidity, viscosity,ground-reference potential, density, concentration, water activity,reduction potential, state of charge, and pH. Such actions can include,without limitation, adding second electrolyte, removing secondelectrolyte, increasing a state of charge and/or pH of the secondelectrolyte, or even decreasing a state of charge and/or pH of secondelectrolyte.

Aspect 26. The flow battery of any one of Aspects 1 to 25, wherein thefirst fluidic network further comprises flow structures selected fromseries subflow structures, parallel subflow structures, shunt currentcontrol subflow structures (such as for shunt current mitigation and/ormanagement), counterflow subflow structures, measurement and otherdiagnostic subflow structures, treatment (such as electrolyterebalancing) subflow structures, source subflow structures, drainsubflow structures, and combinations thereof.

Aspect 27. The flow battery of any one of Aspects 4 to 26, wherein thesecond fluidic network further comprises flow structures selected fromseries subflow structures, parallel subflow structures, shunt currentcontrol subflow structures (such as for shunt current mitigation and/ormanagement), counterflow subflow structures, measurement and otherdiagnostic subflow structures, treatment (such as electrolyterebalancing) subflow structures, source subflow structures, drainsubflow structures, and combinations thereof.

Aspect 28. The flow battery of any one of Aspects 1 to 27, wherein thefirst dynamic fluidic network further comprises flow structures selectedfrom series subflow structures, parallel subflow structures, shuntcurrent control subflow structures (such as for shunt current mitigationand/or management), counterflow subflow structures, measurement subflowstructures, diagnostic subflow structures, treatment (such aselectrolyte rebalancing) subflow structures, source subflow structures,reticulated subflow structures, drain subflow structures, andcombinations thereof.

Aspect 29. The flow battery of any one of Aspects 4 to 27, wherein thesecond dynamic fluidic network further comprises flow structuresselected from series subflow structures, parallel subflow structures,shunt current control subflow structures (such as for shunt currentmitigation and/or management), counterflow subflow structures,measurement subflow structures, diagnostic subflow structures, treatment(such as electrolyte rebalancing) subflow structures, source subflowstructures, reticulated subflow structures, drain subflow structures,and combinations thereof.

Aspect 30. The flow battery of any one of Aspects 1 to 29, wherein thefirst dynamic fluidic network has at least one region where V_(n) andA_(n) values of the subflow structures progressively decrease. Forexample, as discussed earlier with respect to FIGS. 1 and 12 ,V₄>V₆>V₁₁>V₁₂>V₁₄ with the same progression and relationships for theA_(n) values.

Aspect 31. The flow battery of any one of Aspects 4 to 30, wherein thesecond dynamic fluidic network has at least one region where V_(n) andA_(n) values of the subflow structures progressively decrease.

Aspect 32. The flow battery of any one of Aspects 1 to 31, wherein thefirst dynamic fluidic network has at least one region where V_(n) andA_(n) values of the subflow structures progressively increase.

Aspect 33. The flow battery of any one of Aspects 4 to 32, wherein thesecond dynamic fluidic network has at least one region where V_(n) andA_(n) values of the subflow structures progressively increase.

Aspect 34. The flow battery of any one of Aspects 1 to 33, wherein thefirst counterflow structure conveys the first electrolyte to a balancingcell and reintroduces treated first electrolyte into the first dynamicfluidic network.

Aspect 35. The flow battery of any one of Aspects 4 to 34, wherein thesecond counterflow structure conveys the second electrolyte to abalancing cell and reintroduces treated second electrolyte into thesecond dynamic fluidic network.

Aspect 36. The flow battery of any one of Aspects 1 to 35, wherein thefirst dynamic fluidic network further comprises a BPPA and/or an MPPA,each comprising a frame element, an inner plate, and at least:

-   -   (a) five different flow structures on each side of a BPPA or the        one side of an MPPA, or    -   (b) six different flow structures on each side of a BPPA or the        one side of an MPPA, or    -   (c) a combination of (a) and (b). For example, one side of a        BPPA has five different flow structures and the other side has        six different flow structures.

Aspect 37. The flow battery of Aspect 36, wherein the at least sixdifferent flow structures comprise an inlet conduit, an inlet manifold,inlet flow structures, outlet flow structures, an outlet manifold, andan outlet conduit.

Aspect 38. The flow battery of any one of Aspects 4 to 37, wherein thesecond dynamic fluidic network further comprises a BPPA and/or an MPPA,each comprising a frame element and an inner plate havingcharacteristics recited in Aspects 36 and 37.

Aspect 39. The flow battery of Aspect 38 wherein the at least sixdifferent flow structures comprise an inlet conduit, an inlet manifold,inlet flow structures, outlet flow structures, an outlet manifold, andan outlet conduit Aspect 40. The flow battery of either Aspect 37 orAspect 39 wherein an inlet manifold and/or an outlet manifold iselongated, and optionally, has an s-curve configuration.

Aspect 41. The flow battery of any one of Aspects 36 to 40, wherein eachmanifold n has values for a volume V_(n), a cross-sectional area A_(n),a length L_(n), and a path P_(n), such that V_(n), A_(n), L_(n), andP_(n) define a shape of the manifold, and wherein one or more of V_(n),A_(n), L_(n), and P_(n) values may be the same or different betweeninlet and outlet manifolds on the same side of the BPPA or MPPA.

Aspect 42. The flow battery of any one of Aspects 36 to 41 wherein:

-   -   (a) at least one of the inlet conduit, inlet manifold, outlet        manifold, and outlet conduit comprises a shunt current control        subflow structure; or    -   (b) at least two inlet flow structures and/or at least two        outlet flow structures are structurally and fluidically        interconnected within an inner plate; or    -   (c) at least one inlet flow structure and at least one outlet        flow structure and structurally and fluidically interconnected        within an inner plate; or    -   (d) none of the inlet flow structures are structurally        interconnected with each other within an inner plate and/or none        of the outlet flow structures are structurally interconnected        with each other within an inner plate; or    -   (e) the frame element forms a complete, continuous, unitary        perimeter around the inner plate; or    -   (f) inner plate flow structures are interconnected, restricted,        or terminated within the frame element; or    -   (g) the inner plate comprises a conductive material; or    -   (h) the frame element comprises a non-conductive material; or    -   (i) a combination of any two or more of (a) through (h).

Aspect 43. The flow battery of any one of Aspects 36 to 42, wherein eachinner plate flow structure n has values for a volume V_(n), across-sectional area A_(n), a length L_(n), and a path P_(n), such thatV_(n), A_(n), L_(n), and P_(n) define a shape of the flow structure andwherein one or more of V_(n), A_(n), L_(n), and P_(n) values may be thesame or different between inlet and outlet flow structures on the sameside of the BPPA or MPPA.

Aspect 44. The flow battery of Aspect 40, wherein each flow channel nhas values for a volume V_(n), a cross-sectional area A_(n), a lengthL_(n), and a path P_(n), such that V_(n), A_(n), L_(n), and P_(n) definea shape of the flow channel and wherein one or more of V_(n), A_(n),L_(n), and P_(n) values may be the same or different between inlet andoutlet flow channels on different sides of the BPPA.

Aspect 45. The flow battery of any one of Aspects 40 to 44, wherein theinner plate of each side of the BPPA and the MPPA comprises a firstinlet flow structure, a second inlet flow structure, a third inlet flowstructure, and a fourth inlet flow structure, etc., which may be thesame or different from each other in terms of V_(n), A_(n), L_(n), andP_(n) values, and a first outlet flow structure, a second outlet flowstructure, a third outlet flow structure, and a fourth outlet flowstructure, etc., which may be the same or different from each other interms of V_(n), A_(n), L_(n), and P_(n) values.

Aspect 46. The flow battery of any one of Aspects 36 to 45, wherein theat least six different flow structures on a side of a BPPA or MPPAcomprise a first subflow structure and a second subflow structurewherein the flow structures of each subflow structure are structurallyand fluidically connected in series.

Aspect 47. The flow battery of any one of Aspects 40 to 46, wherein theinner plates of each side of a BPPA may have the same or differentpatterns or configurations of inlet and/or outlet flow structures.Similarly, the inner plates of MPPAs with opposite polarity may have thesame or different patterns or configurations of inlet and/or outlet flowstructures.

Aspect 48. The flow battery of Aspect 46, wherein each of the firstsubflow structure and the second subflow structure is an integral,unitary subflow structure and collectively comprise a plate subflowstructure.

Aspect 49. The flow battery of any one of Aspects 36 to 48, wherein oneor more of the inlet manifolds has holes that communicate fluidicallywith one or more inlet flow structures. Optionally, the fluidiccommunication may be accomplished through a plenum.

Aspect 50. The flow battery of any one of Aspects 36 to 49, wherein oneor more of the outlet manifolds has holes that communicate fluidicallywith one or more outlet flow structures. Optionally, the fluidiccommunication may be accomplished through a plenum.

Aspect 51. A flow battery system comprising at least one flow batterysystem comprising at least one ancillary system and at least one flowbattery of any one of Aspects 1 to 50.

Aspect 52. A flow battery system of Aspect 51, wherein the at least oneflow battery system and two or more flow batteries are in series, inparallel, or in series and in parallel. When flow batteries of thepresent disclosure are in series and/or in parallel, they may havecommon features. Non-limiting examples include two flow batteries of thepresent disclosure having a common main electrolyte source for anelectrolyte or a common dynamic fluidic network for the electrolyte.

Aspect 53. A method, comprising: with a flow battery according to anyone of Aspects 1 to 50, placing the first fluidic train into its secondstate and determining a characteristic of first electrolyte disposedwithin the first sampling segment when the first fluidic train is in itssecond state.

Aspect 54. A method of Aspect 53, further comprising placing the secondfluidic train into its second state and determining a characteristic ofsecond electrolyte disposed within the second sampling segment when thesecond fluidic train is in its second state.

Aspect 55. A method, comprising: with a flow battery according to anyone of Aspects 4 to 50, placing the second fluidic train into its secondstate and determining a characteristic of second electrolyte disposedwithin the second sampling segment when the second fluidic train is inits second state.

Aspect 56. The method of any one of Aspects 53 to 55, wherein thecharacteristic of first electrolyte and/or second electrolyte isselected from pressure, conductivity, color, temperature, turbidity,viscosity, ground-reference potential, density, concentration, wateractivity, oxidation-reduction potential, pH, state of charge, andcombinations thereof.

Aspect 57. A method comprising: with a flow battery having a first halfand a second half, the first half comprising a first main electrolytesource, a first electrolyte, and a first dynamic fluidic networkcomprising a first counterflow structure, a first electrode region and afirst fluidic train that is convertible between a first state and asecond state and has a first sampling segment, converting the firstfluidic train from its first state, with the first main electrolytesource and the first dynamic fluidic network, outside the first fluidictrain and first electrode region, in fluid communication with the firstelectrode region, to its second state, with the first main electrolytesource and the first dynamic fluidic network, outside the first fluidictrain and first electrode region, in fluid isolation from the firstelectrode region; and while the first fluidic train is in its secondstate, determining a characteristic of first electrolyte that is influid communication with the first electrode region.

Alternatively, in lieu of the first counterflow structure, the firstdynamic fluidic network may have flow structures selected from seriessubflow structures, parallel subflow structures, shunt current controlsubflow structures (such as for shunt current mitigation and/ormanagement), measurement subflow structures, diagnostic subflowstructures, treatment (such as electrolyte rebalancing) subflowstructures, source subflow structures, reticulated subflow structures,drain subflow structures, and combinations thereof.

Aspect 58. A method of Aspect 57, further comprising with the secondhalf comprising a second main electrolyte source, a second electrolyte,and a second dynamic fluidic network comprising a second counterflowstructure, a second electrode region, and a second fluidic train that isconvertible between a first state and a second state and has a secondsampling segment, converting the second fluidic train from its firststate, with the second main electrolyte source and the second dynamicfluidic network, outside the second fluidic train and second electroderegion, in fluid communication with the second electrode region, to itssecond state, with the second main electrolyte source and the seconddynamic fluidic network, outside the second fluidic train and secondelectrode region, in fluid isolation from the second electrode region;and while the second fluidic train is in its second state, determining acharacteristic of second electrolyte that is in fluid communication withthe second electrode region.

Alternatively, in lieu of the second counterflow structure, the seconddynamic fluidic network may have flow structures selected from seriessubflow structures, parallel subflow structures, shunt current controlsubflow structures (such as for shunt current mitigation and/ormanagement), measurement subflow structures, diagnostic subflowstructures, treatment (such as electrolyte rebalancing) subflowstructures, source subflow structures, reticulated subflow structures,drain subflow structures, and combinations thereof.

Aspect 59. A method comprising: with a flow battery having a first halfand a second half, the second half comprising a second main electrolytesource, a second electrolyte, and a second dynamic fluidic networkcomprising a second counterflow structure, a second electrode region anda second fluidic train that is convertible between a first state and asecond state and has a second sampling segment, converting the secondfluidic train from its first state, with the second main electrolytesource and the second dynamic fluidic network, outside the secondfluidic train and second electrode region, in fluid communication withthe second electrode region, to its second state, with the second mainelectrolyte source and the second dynamic fluidic network, outside thesecond fluidic train and second electrode region, in fluid isolationfrom the second electrode region; and while the second fluidic train isin its second state, determining a characteristic of second electrolytethat is in fluid communication with the second electrode region.

Alternatively, in lieu of the second counterflow structure, the seconddynamic fluidic network may have flow structures selected from seriessubflow structures, parallel subflow structures, shunt current controlsubflow structures (such as for shunt current mitigation and/ormanagement), measurement subflow structures, diagnostic subflowstructures, treatment (such as electrolyte rebalancing) subflowstructures, source subflow structures, reticulated subflow structures,drain subflow structures, and combinations thereof.

Aspect 60. The method of any one of Aspects 57 to 59, wherein thedetermined characteristic of first electrolyte and/or second electrolyteis selected from pressure, conductivity, color, temperature, turbidity,viscosity, ground-reference potential, density, concentration, wateractivity, oxidation-reduction potential, pH, state of charge, andcombinations thereof.

Aspect 61. The method of any one of Aspects 57 to 60, further comprisingeffecting an action in response to the determined characteristic offirst electrolyte that is in fluid communication with the firstelectrode region while the first fluidic train is in its second state.The method can include, without limitation, adding first electrolyte,removing first electrolyte, increasing a state of charge of the firstelectrolyte, or even to decreasing a state of charge of firstelectrolyte, and other aspects of electrolyte balancing.

Aspect 62. The method of any one of Aspects 58 to 61, further comprisingeffecting an action in response to the determined characteristic ofsecond electrolyte that is in fluid communication with the secondelectrode region while the second fluidic train is in its second state.The method can include, without limitation, adding second electrolyte,removing second electrolyte, increasing a state of charge of the secondelectrolyte, or even to decreasing a state of charge of secondelectrolyte, and other aspects of electrolyte balancing.

Aspect 63. The method of any one of Aspects 57 to 62, further comprisingconverting the first fluidic train from its second state to its firststate.

Aspect 64. The method of any one of Aspects 57 to 63, wherein the methodis performed in an automated fashion.

Aspect 65. The method of any one of Aspects 57 to 64, wherein the methodis performed manually.

Aspect 66. The method of any one of Aspects 57 to 65, further comprisingassessing a level of crossover between the first main electrolyte sourceand another main electrolyte source while the first fluidic train is inits second state.

Aspect 67. The method of any one of Aspects 58 to 66, further comprisingconverting the second fluidic train from its second state to its firststate.

Aspect 68. The method of any one of Aspects 58 to 67, wherein the methodis performed in an automated fashion.

Aspect 69. The method of any one of Aspects 58 to 68, wherein the methodis performed manually.

Aspect 70. The method of any one of Aspects 58 to 69, further comprisingassessing a level of crossover between the second main electrolytesource and another main electrolyte source while the second fluidictrain is in its second state.

Aspect 71. The method of any one of Aspects 53 to 70 wherein a flowbattery comprises a BPPA or MPPA in an electrode region, the BPPA orMPPA comprising a frame element, an inner plate, and each side of a BPPAor the side of an MPPA comprises at least six different flow channels.

Aspect 72. A flow battery comprising: a dynamic fluidic network systemcomprising a first dynamic fluidic network and second fluidic network;wherein the flow battery has a first half and a second half, the firsthalf comprising (i) a first main electrolyte source configured tocontain a first electrolyte, (ii) a first electrode region configuredfor electronic communication with the first electrolyte, and (iii) thefirst dynamic fluidic network configured for fluid communication withthe first main electrolyte source and comprising the first electroderegion, a first diagnostic subflow structure, and a first treatmentsubflow structure, and the second half comprising (i) a second mainelectrolyte source configured to contain a second electrolyte, (ii), asecond electrode region configured for electronic communication with thesecond electrolyte, and (iii) the second fluidic network configured forfluid communication with the second main electrolyte source andcomprising the second electrode region and a second diagnostic subflowstructure, and a second treatment subflow structure.

Aspect 73. The flow battery of Aspect 72, wherein the first diagnosticsubflow structure comprises (i) one or more instruments configured todetermine a characteristic of first electrolyte disposed within thefirst diagnostic subflow structure, (ii) one or more instrumentsconfigured to determine a characteristic of first electrolyte that isnot disposed within the first diagnostic subflow structure, or both (i)and (ii).

Aspect 74. The flow battery of any one of Aspects 72 to 73, wherein thesecond diagnostic subflow structure comprises (i) one or moreinstruments configured to determine a characteristic of secondelectrolyte disposed within the second diagnostic subflow structure,(ii) one or more instruments configured to determine a characteristic ofsecond electrolyte that is not disposed within the second diagnosticsubflow structure, or both (i) and (ii).

Aspect 75. The flow battery of Aspect 73, wherein the characteristic offirst electrolyte is selected from pressure, conductivity, color,temperature, turbidity, viscosity, ground-reference potential, density,concentration, water activity, oxidation-reduction potential, pH, stateof charge, and combinations thereof.

Aspect 76. The flow battery of Aspect 73, wherein the first diagnosticsubflow structure comprises both (i) and (ii) and the characteristicdetermined by (i) is the same as the characteristic determined by (ii).

Aspect 77. The flow battery of Aspect 74, wherein the characteristic ofsecond electrolyte is selected from pressure, conductivity, color,temperature, turbidity, viscosity, ground-reference potential, density,concentration, water activity, oxidation-reduction potential, pH, stateof charge, and combinations thereof.

Aspect 78. The flow battery of Aspect 74, wherein the second diagnosticsubflow structure comprises both (i) and (ii) and the characteristicdetermined by (i) is the same as the characteristic determined by (ii).

Aspect 79. The flow battery of any one of Aspects 72 to 78, furthercomprising a first pump or pneumatic system configured to clear firstelectrolyte from the first diagnostic subflow structure and/or the firsttreatment subflow structure.

Aspect 80. The flow battery of any one of Aspects 72 to 79, furthercomprising a second pump or pneumatic system configured to clear secondelectrolyte from the second diagnostic subflow structure and/or thesecond treatment subflow structure.

Aspect 81. The flow battery of any one of Aspects 72 to 80, wherein theflow battery is configured to effect an action by the first treatmentsubflow structure in response to a determined characteristic of firstelectrolyte that is in fluid communication with the first diagnosticsubflow structure.

Aspect 82. The flow battery of any one of Aspects 72 to 81, wherein theflow battery is configured to effect an action by the second treatmentsubflow structure in response to a determined characteristic of secondelectrolyte that is in fluid communication with the second diagnosticsubflow structure.

Aspect 83. The flow battery of any one of Aspects 72 to 82, wherein thefirst dynamic fluidic network further comprises flow structures selectedfrom series subflow structures, parallel subflow structures, shuntcurrent control subflow structures (such as for shunt current mitigationand/or management), counterflow subflow structures, measurement subflowstructures, diagnostic subflow structures, treatment subflow structures,source subflow structures, reticulated subflow structures, drain subflowstructures, and combinations thereof.

Aspect 84. The flow battery of any one of Aspects 72 to 83, wherein thefirst dynamic fluidic network further comprises a BPPA or an MPPA,comprising said first diagnostic subflow structure and said firsttreatment subflow structure Aspect 85. The flow battery of Aspect 84,wherein the BPPA or the MPPA further comprises an inlet conduit, aninlet manifold, a flow plate, an outlet manifold, and an outlet conduit.

Aspect 86. The flow battery of Aspect 85, wherein the inlet manifoldand/or the outlet manifold has an s-curve configuration.

Aspect 87. The flow battery of any one of Aspects 72 to 86, wherein thesecond fluidic network is a dynamic fluidic network.

Aspect 88. The flow battery of Aspect 87, wherein the second dynamicfluidic network further comprises flow structures selected from seriessubflow structures, parallel subflow structures, shunt current controlsubflow structures (such as for shunt current mitigation and/ormanagement), counterflow subflow structures, measurement subflowstructures, diagnostic subflow structures, treatment subflow structures,source subflow structures, reticulated subflow structures, drain subflowstructures, and combinations thereof.

Aspect 89. The flow battery of Aspect 88, wherein the second dynamicfluidic network further comprises a BPPA or an MPPA, comprising saidsecond diagnostic subflow structure and said second treatment subflowstructure.

Aspect 90. The flow battery of Aspect 89, wherein the BPPA or the MPPAfurther comprises an inlet conduit, an inlet manifold, a flow plate, anoutlet manifold, and an outlet conduit.

Aspect 91. The flow battery of Aspect 90, wherein the inlet manifoldand/or the outlet manifold has an s-curve configuration.

Aspect 92. The flow battery of any one of Aspects 72 to 91, wherein oneor more of the first diagnostic subflow structure, the first treatmentsubflow structure, the second diagnostic subflow structure, the secondtreatment subflow structure is an isolated subflow structure.

Aspect 93. A flow battery comprising: a dynamic fluidic network systemcomprising a first dynamic fluidic network, the first dynamic fluidicnetwork comprising an inner plate flow structure comprising a firstshunt current control subflow structure. The first dynamic fluidicnetwork may comprise two or more inner plate flow structures. Each innerflow plate structures may comprise one or more shunt current controlsubflow structures.

Aspect 94. The flow battery of Aspect 93, wherein the first shuntcurrent control subflow structure is a component of a first shuntcurrent control system. A first shunt current control system maycomprise one or more first shunt current control subflow structures, oneor more first shunt current mitigation subflow structures, and/or one ormore first shunt current management subflow structures.

Aspect 95. The flow battery of Aspect 94, wherein the first shuntcurrent control system further comprises an inlet manifold, an outletmanifold, or both inlet and outlet manifolds.

Aspect 96. The flow battery of Aspect 95, wherein the first shuntcurrent control system further comprises a first balancing cell.

Aspect 97. The flow battery of Aspect 93, wherein the dynamic fluidicnetwork system further comprises a second fluidic network.

Aspect 98. The flow battery of Aspect 97, wherein the second fluidicnetwork is a dynamic fluidic network.

Aspect 99. The flow battery of Aspect 98, wherein the second dynamicfluidic network comprising an inner plate flow structure comprising asecond shunt current control subflow structure, which is a component ofa second shunt current control system. The second dynamic fluidicnetwork may comprise two or more inner plate flow structures. Each innerflow plate structures may comprise one or more shunt current controlsubflow structures. A second shunt current control system may compriseone or more second shunt current control subflow structures, one or moresecond shunt current mitigation subflow structures, and/or one or moresecond shunt current management subflow structures.

Aspect 100. The flow battery of Aspect 99, wherein the second shuntcurrent control system further comprises an inlet manifold, an outletmanifold, or both inlet and outlet manifolds.

Aspect 101. The flow battery of Aspect 100, wherein second first shuntcurrent control system further comprises a second balancing cell.

Aspect 102. A flow battery comprising a dynamic fluidic network systemcomprising a first dynamic fluidic network, the first dynamic fluidicnetwork comprising a first counterflow structure.

Aspect 103. The flow battery of Aspect 102, wherein the firstcounterflow structure comprises an instrument selected from monitors,sensors, and processors configured to determine a characteristic of afirst electrolyte disposed within the first counterflow structure.

Aspect 104. The flow battery of Aspect 103, wherein the characteristicof the first electrolyte is selected from pressure, conductivity, color,temperature, turbidity, viscosity, ground-reference potential, density,concentration, water activity, oxidation-reduction potential, pH, stateof charge, and combinations thereof.

Aspect 105. The flow battery of Aspect 102, wherein the dynamic fluidicnetwork system further comprises a second fluidic network.

Aspect 106. The flow battery of Aspect 105, wherein the second fluidicnetwork is a dynamic fluidic network.

Aspect 107. The flow battery of Aspect 105, wherein the second dynamicfluidic network comprising a second counterflow structure.

Aspect 108. The flow battery of Aspect 107, wherein the secondcounterflow structure comprises an instrument selected from monitors,sensors, and processors configured to determine a characteristic of asecond electrolyte disposed within the second counterflow structure.

Aspect 109. The flow battery of Aspect 108, wherein the characteristicof the second electrolyte is selected from pressure, conductivity,color, temperature, turbidity, viscosity, ground-reference potential,density, concentration, water activity, oxidation-reduction potential,pH, state of charge, and combinations thereof.

Aspect 110. The flow battery of any one of Aspects 102 to 109, whereinthe first counterflow structure comprises a balancing cell.

Aspect 111. The flow battery of any one of Aspects 107 to 109, whereinthe second counterflow structure comprises a balancing cell.

Aspect 112. The flow battery of any one of Aspects 102 to 111, whereinthe first counterflow structure is configured such that a flow ofelectrolyte through the first counterflow structure is counter to a flowof electrolyte from a first main electrolyte source to a first electroderegion to the first main electrolyte source.

Aspect 113. The flow battery of any one of Aspects 102 to 111, whereinthe first counterflow structure is configured such that the flow ofelectrolyte through the first counterflow structure is concurrent to aflow of electrolyte from a first main electrolyte source to a firstelectrode region to the first main electrolyte source.

Aspect 114. The flow battery of any one of Aspects 102 to 111, whereinthe first counterflow structure is configured to operate alternativelyin two states: (i) wherein a flow of electrolyte through the firstcounterflow structure is counter to a flow of electrolyte from a firstmain electrolyte source to a first electrode region to the first mainelectrolyte source, and (ii) wherein a flow of electrolyte through thefirst counterflow structure is concurrent to a flow of electrolyte froma first main electrolyte source to a first electrode region to the firstmain electrolyte source.

Aspect 115. The flow battery of any one of Aspects 107 to 114, whereinthe second counterflow structure is configured such that a flow ofelectrolyte through the second counterflow structure is counter to aflow of electrolyte from a second main electrolyte source to a secondelectrode region to the second main electrolyte source.

Aspect 116. The flow battery of any one of Aspects 107 to 111, whereinthe second counterflow structure is configured such that the flow ofelectrolyte through the second counterflow structure is concurrent to aflow of electrolyte from a second main electrolyte source to a secondelectrode region to the second main electrolyte source.

Aspect 117. The flow battery of any one of Aspects 107 to 111, whereinthe second counterflow structure is configured to operate alternativelyin two states: (i) wherein a flow of electrolyte through the secondcounterflow structure is counter to a flow of electrolyte from a secondmain electrolyte source to a second electrode region to the second mainelectrolyte source, and (ii) wherein a flow of electrolyte through thesecond counterflow structure is concurrent to a flow of electrolyte froma second main electrolyte source to a second electrode region to thesecond main electrolyte source.

Aspect 118. The flow battery of any one of Aspects 102 to 117, whereinthe first counterflow structure is in fluid communication with a portionof the first dynamic fluidic network when the portion of the firstdynamic fluidic network is in fluid isolation from the remainder of thefirst dynamic fluidic network.

Aspect 119. The flow battery of Aspect 118, wherein the firstcounterflow structure is configured to reintroduce electrolyte from thefirst counterflow structure to the remainder of the first dynamicfluidic network after treatment of the electrolyte with a firstbalancing cell.

Aspect 120. The flow battery of any one of Aspects 107 to 117, whereinthe second counterflow structure is in fluid communication with aportion of the second dynamic fluidic network when the portion of thesecond dynamic fluidic network is in fluid isolation from the remainderof the second dynamic fluidic network.

Aspect 121. The flow battery of Aspect 120, wherein the secondcounterflow structure is configured to reintroduce electrolyte from thesecond counterflow structure to the remainder of the second dynamicfluidic network after treatment of the electrolyte with a secondbalancing cell.

Aspect 122. The flow battery of any one of Aspects 102 to 121, whereinthe first counterflow structure further comprises a first pump.

Aspect 123. The flow battery of any one of Aspects 102 to 122, whereinthe first dynamic fluidic network further comprises one or more flowstructures selected from series subflow structures, parallel subflowstructures, shunt current control subflow structures, counterflowsubflow structures, measurement subflow structures, diagnostic subflowstructures, treatment subflow structures, source subflow structures,reticulated subflow structures, drain subflow structures, andcombinations thereof.

Aspect 124. The flow battery of any one of Aspects 107 to 123, whereinthe second counterflow structure further comprises a second pump.

Aspect 125. The flow battery of any one of Aspects 107 to 124, whereinthe second dynamic fluidic network further comprises one or more flowstructures selected from series subflow structures, parallel subflowstructures, shunt current control subflow structures, counterflowsubflow structures, measurement subflow structures, diagnostic subflowstructures, treatment subflow structures, source subflow structures,reticulated subflow structures, drain subflow structures, andcombinations thereof.

Aspect 126. A flow battery system comprising a stack of one or more flowbatteries of any one of Aspects 1 to 71 and 93-125. A flow batterysystem may comprise a stack of two or more flow batteries.

Aspect 127. The flow battery system Aspect 126, further comprising adiagnostic subflow structure, a treatment subflow structure, performancecontrols, control hardware and software, and a power conditioning unit.

Having now described some aspects of the disclosure, it should beapparent to those skilled in the art that the foregoing is merelyillustrative and not limiting, having been presented by way of exampleonly. Numerous modifications and other aspects are within the scope ofone of ordinary skill in the art and are contemplated as falling withinthe scope of the present disclosure. In particular, although many of theexamples presented herein involve specific combinations of method actsor system elements, it should be understood that those acts and thoseelements may be combined in other ways to accomplish the same or similarobjectives.

1-64. (canceled)
 65. A flow battery comprising: a first half and asecond half, the first half comprising (i) a first main electrolytesource configured to contain a first electrolyte, (ii) a first electroderegion configured for electronic communication with the firstelectrolyte, and (iii) a first dynamic fluidic network configured forfluid communication with the first main electrolyte source andcomprising the first electrode region, wherein the flow battery isconfigured to remove the first electrolyte from the first electroderegion, while the first electrode region is in fluid isolation from thefirst main electrolyte source.
 66. The flow battery of claim 65, whereinthe flow battery is configured for local draining of the first electroderegion, without draining portions of the first dynamic fluidic network.67. The flow battery of claim 65, further comprising a first fluidictrain comprising a first sampling segment and a first treatment subflowstructure.
 68. The flow battery of claim 67, wherein the first samplingsegment comprises (i) one or more first instruments configured todetermine a characteristic of the first electrolyte disposed within thefirst sampling segment, (ii) one or more second instruments configuredto determine a characteristic of the first electrolyte that is disposedoutside the first sampling segment, or both (i) and (ii).
 69. The flowbattery of claim 68, wherein the characteristic of the first electrolyteis selected from pressure, conductivity, color, temperature, turbidity,viscosity, ground-reference potential, density, concentration, wateractivity, oxidation-reduction potential, pH, state of charge, andcombinations thereof.
 70. The flow battery of claim 69, wherein thecharacteristic determined by the one or more first instruments is thesame as the characteristic determined by the one or more secondinstruments.
 71. The flow battery of claim 67, wherein the firstelectrode region has an enclosed volume, wherein the first fluidic trainhas an enclosed volume, and wherein the ratio of the enclosed volume ofthe first electrode region and the enclosed volume of the first fluidictrain is from about 1:1000 to about 1:1.
 72. The flow battery of claim67, wherein the first main electrolyte source has an enclosed volume,wherein the first fluidic train has an enclosed volume, and wherein theratio of the enclosed volume of the first fluidic train and the enclosedvolume of the first main electrolyte source is from about 1:100,000 toabout 1:1.
 73. The flow battery of claim 67, wherein the first fluidictrain further comprises a pump or a pneumatic system configured toremove the first electrolyte from the first electrode region.
 74. Theflow battery of claim 67, wherein the flow battery is configured toeffect an action in response to a determined characteristic of the firstelectrolyte that is in fluid communication with the first electroderegion.
 75. The flow battery of claim 67, wherein the first dynamicfluidic network further comprises flow structures selected from seriessubflow structures, parallel subflow structures, shunt current controlsubflow structures, counterflow subflow structures, measurement subflowstructures, diagnostic subflow structures, treatment subflow structures,source subflow structures, reticulated subflow structures, drain subflowstructures, and combinations thereof.
 76. The flow battery of claim 67,wherein the first dynamic fluidic network has at least one region of nsubflow structures, each with a volume V_(n) and a cross-sectional areaA_(n), where the V_(n) and A_(n) values of the subflow structuresprogressively decrease.
 77. The flow battery of claim 67, wherein thefirst dynamic fluidic network has at least one region of n subflowstructures, each with a volume V_(n) and a cross-sectional area A_(n),where the V_(n) and A_(n) values of the subflow structures progressivelyincrease.
 78. The flow battery of claim 67, the first dynamic fluidicnetwork further comprises a first counterflow structure that conveys thefirst electrolyte of the first dynamic fluidic network to a balancingcell and reintroduces treated first electrolyte into the first dynamicfluidic network.
 79. The flow battery of claim 67, wherein the firstdynamic fluidic network further comprises a BPPA and/or an MPPA, eachwith at least one side comprising an inlet conduit, an inlet manifold, aflow plate, an outlet manifold, and an outlet conduit.
 80. The flowbattery of claim 79, wherein the inlet manifold and/or the outletmanifold has an s-curve configuration.
 81. The flow battery of claim 67,wherein the first dynamic fluidic network further comprises a BPPAand/or MPPA, each comprising a frame element, an inner plate, and atleast five different flow structures on at least one side of each BPPA'sinner plate or on one side of each MPPA's inner plate
 82. The flowbattery of claim 81, wherein one side of each BPPA's inner plate hasfive different flow structures and the other side has six different flowstructures.
 83. The flow battery of claim 81, wherein each side of eachBPPA's inner plate and the one side of each MPPA's inner plate has atleast six different flow structures and wherein the at least sixdifferent flow structures comprise an inlet conduit, an inlet manifold,inlet flow structures, outlet flow structures, an outlet manifold, andan outlet conduit.
 84. The flow battery of claim 83, wherein eachmanifold n has values for a volume V_(n), a cross-sectional area A_(n),a length L_(n), and a path P_(n), such that V_(n), A_(n), L_(n), andP_(n) define a shape of the manifold, and wherein one or more of V_(n),A_(n), L_(n), and P_(n) values may be the same or different betweeninlet and outlet manifolds on the same side of the BPPA or MPPA or onopposite sides of a BPPA.
 85. The flow battery of claim 83, wherein forat least one side of the BPPA's inner plate and/or MPPA's inner plate:(a) at least one of the inlet conduit, inlet manifold, outlet manifold,and outlet conduit comprises a shunt current control subflow structure;or (b) at least two inlet flow structures and/or at least two outletflow structures are structurally and fluidically interconnected withinthe inner plate; or (c) at least one inlet flow structure and at leastone outlet flow structure are structurally and fluidicallyinterconnected within the inner plate; or (d) none of the inlet flowstructures are structurally interconnected with each other within aninner plate and/or none of the outlet flow structures are structurallyinterconnected with each other within the inner plate; or (e) the frameelement forms a complete, continuous, unitary perimeter around the innerplate; or (f) inner plate flow structures are interconnected,restricted, or terminated within the frame element; or (g) the innerplate comprises a conductive material; or (h) the frame elementcomprises a non-conductive material; or (i) a combination of any two ormore of (a) through (h).
 86. The flow battery of claim 81, wherein: (a)each inner plate has n flow structures each having values for a volumeV_(n), a cross-sectional area A_(n), a length L_(n), and a path P_(n),such that V_(n), A_(n), L_(n), and P_(n) define a shape of each flowstructure, and wherein one or more of V_(n), A_(n), L_(n), and P_(n)values may be the same or different between inlet and outlet flowstructures on the same side of the BPPA's or MPPA's inner plate, or onopposite sides of the BPPA's inner plate, or (b) each inner plate has nflow structures each having values for a volume V_(n), a cross-sectionalarea A_(n), a length L_(n), and a path P_(n), such that V_(n), A_(n),L_(n), and P_(n) define a shape of each flow structure and wherein oneor more of V_(n), A_(n), L_(n), and P_(n) values may be the same ordifferent between inlet and outlet flow channels on the same ordifferent sides of the BPPA's inner plate.
 87. The flow battery of claim65, wherein the first main electrolyte source is a single mainelectrolyte source.
 88. The flow battery of claim 65, wherein the secondhalf comprises (i) a second main electrolyte source configured tocontain a second electrolyte, and (ii) a second electrode regionconfigured for electronic communication with the second electrolyte, and(iii) a second dynamic fluidic network configured for fluidcommunication with the second main electrolyte source and comprising thesecond electrode region, wherein the flow battery is configured toremove the second electrolyte from the second electrode region, whilethe second electrode region is in fluid isolation from the second mainelectrolyte source.
 89. The flow battery of claim 88, wherein the flowbattery is configured for local draining of the second electrode region,without draining portions of the second dynamic fluidic network.
 90. Theflow battery of claim 88, further comprising a second fluidic traincomprising a second sampling segment and a second treatment subflowstructure.
 91. The flow battery of claim 90, wherein the second samplingsegment comprises (i) one or more first instruments configured todetermine a characteristic of the second electrolyte disposed within thesecond sampling segment, (ii) one or more second instruments configuredto determine a characteristic of the second electrolyte that is disposedoutside the second sampling segment, or both (i) and (ii).
 92. The flowbattery of claim 90, wherein the second dynamic fluidic network furthercomprises a BPPA and/or an MPPA, each with at least one side comprisingan inlet conduit, an inlet manifold, a flow plate, an outlet manifold,and an outlet conduit.
 93. The flow battery of claim 88, wherein thesecond main electrolyte source is a single main electrolyte source. 94.A flow battery system comprising at least two flow batteries of claim88.